A) Children may be harmed by the rooks<p>B) Children may be tempted to drop litter</p><p>C) Children may contract bird diseases</p><p>D) Children may overfeed the rooks</p>

A . making a structural change to the vessel B . a short circuit near the compass C . belt buckles D . All of the above

A . Clogged oil pump suction screens B . Increased oil operating temperatures C . Sticking piston rings D . All of the above

A . The persence of cirrus clouds B . The low-hanging stratus clouds C . The altocumulus clouds D . The massive cumulus cloud

A . removing loose water B . adding weight low in the vessel C . closing crossover valves between partly filled double bottom tanks D . All of the above

A . changing pump discharge pressure in response to normal load variations B . a high oil level C . incorrect fluid viscosity D . continued slow re-circulation of the oil

A . numbered B . lettered C . green D . red

A . very quick flashing B . flashing C . fixed D . occulting

A . to B . on C . with D . for

A . to raise water level B . only while making steam C . to remove scum D . when fire are secured

A . lettered B . spherical C . showing a white light D . All of the above

A . under existing visibility conditions B . under perfect visibility C . with ten miles visibility D . with fifteen miles visibility

A . found in the center(s) of the compass rose(s) B . indicated by isogonic lines C . found in a note on the chart D . All of the above

A . tug's engineroom or the bow B . pilot house or aft steering station C . forecastle D . towing bitts by reaching over and releasing a lever

children may not enjoy (to eat) sweets after a meal (so much as) (at) other times, but it is healthier for them (to do) so. A．to eat B．so much as C．at D．to do

A．A.When to leave a plac B．B.Where the meetings ar C．C.What to have for lunc D．D.

Question 1 to 5 are based on the following passage. If you think a high-factor sunscreen(防晒霜)keeps you safe from harmful rays, you may be wrong. Research in this week&39;s Nature shows that while factor 50 reduces the number of melanomas(黑瘤)and delays their occurrence, it can&39;t prevent them. Melanomas are the most aggressive skin cancers. You have a higher risk if you have red or blond hair, fair skin, blue or green eyes, or sunburn easily, or if a close relative has had one. Melanomas are more common if you have periodic intense exposure to the sun. Other skin cancers are increasingly likely with long-term exposure. There is continuing debate as to how effective sunscreen is in reducing melanomas—the evidence is weaker than it is for preventing other types of skin cancer. A 2011 Australian study of 1,621 people found that people randomly selected to apply sunscreen daily had half the rate of melanomas of people who used cream as needed. A second study, comparing 1,167 people with melanomas to 1,101 who didn&39;t have the cancer, found that using sunscreen routinely, alongside other protection such as hats, long sleeves or staying in the shade, did give some protection. This study said other forms of sun protection—not sunscreen—seemed most beneficial. The study relied on people remembering what they had done over each decade of their lives, so it&39;s not entirely reliable. But it seems reasonable to think sunscreen gives people a false sense of security in the sun. Many people also don&39;t use sunscreen properly-applying insufficient amounts, failing to reapply after a couple of hours and staying in the sun too long. It is sunburn that is most worrying-recent shows five episodes of sunburn in the teenage years increases the risk of all skin cancers. The good news is that a combination of sunscreen and covering up can reduce melanoma rates, as shown by Australian figures from their slip-slop-slap campaign. So if there is a heat wave this summer, it would be best for us, too, to slip on a shirt, slop on(抹上)sunscreen and slap on a hat. 1.What is people&39;s common expectation of a high-factor sunscreen？ A.It will delay the occurrence of skin cancer. B.It will protect them from sunburn. C.It will keep their skin smooth and fair. D.It will work for people of any skin color. 2.What does the research in Nature say about a high-factor sunscreen？ A.It is ineffective in preventing melanomas. B.It is ineffective in case of intense sunlight. C.It is ineffective with long-term exposure. D.It is ineffective for people with fair skin. 3.What do we learn from the 2011Australian study of 1,621 people？ A.Sunscreen should be applied alongside other protection measures. B.High-risk people benefit the most from the application of sunscreen. C.Irregular application of sunscreen does women more harm than good. D.Daily application of sunscreen helps reduce the incidence of melanomas. 4.What does the author say about the second Australian study？ A.It misleads people to rely on sunscreen for protection. B.It helps people to select the most effective sunscreen. C.It is not based on direct observation of the subjects. D.It confirms the results of the first Australian study. 5.What does the author suggest to reduce melanoma rates？ A.Using both covering up and sunscreen. B.Staying in the shade whenever possible. C.Using covering up instead of sunscreen. D.Applying the right amount of sunscreen.

A．They are closer to where toxic chemicals remain. B．Particles are more likely to cling to their hands. C．Their immune system is not fully developed. D．They haven't formed a good health habit yet.

This year's crop of 23 entrants were offered an even greater incentive—a $2m prize for the winner. That, plus the intervening 18 months, seems to have done the trick. This time, five vehicles finished the 211 km course. The winner, a modified Volkswagen Touareg dubbed Stanley by its makers, a team from Stanford University, did it in a mere six hours and 54 minutes. Stanley was, of course, specially hardened by its designers for the rough terrain of the Nevada desert. The clever bit, however, was the vehicle's brain. This was designed and built by the Stanford Artificial Intelligence Laboratory (SAIL). Stanley's brain consists of six top-of-the-range Pentium chips wired collaboratively together. It is programmed with special software that is able to learn from its mistakes. This software mastered the tricks of collision-avoidance in a series of desert test runs conducted before the race started. Like all brains, Stanley's has a range of sensory inputs to process. A global positioning system (GPS) receiver tells it where on the Earth's surface it is. Television cameras, radar and four laser based distance monitors tell it what its surroundings are like. By comparing its GPS location with its pre-programmed destination (announced only a few hours before the race began), it knew which way it wanted to go. And, by studying its surroundings, it could work out what looked like the safest route that was also in approximately the right direction. Although Stanley carried off the laurels, the other four finishers did respectably. Sandstorm managed a time just ten minutes behind the winner while her sister vehicle Highlander came in ten minutes after that. GrayBot and TerraMax, the other two course-completers, came in at seven hours 30 minutes and 12 hours 51 minutes, respectively. So smart, autonomous vehicles can, indeed, find their way across several hundred kilometres of desert. The question is, what next？ DARPA's answer, of course, will be to go down the military route. But this sort of technology has obvious civilian applications as well, as Sebastian Thrun, the head of both SAIL and the Stanford racing team, is keen to emphasize. Dr. Thrun thinks that it could lead to self-driving road vehicles within 30 years and—more immediately—to greatly improved collision-avoidance systems. Whether the freeways of California will prove as easy to navigate as the gulches of Nevada, though, remains to be seen. The purpose of holding a robot race is to A．adventure through the Nevada desert. B．delevop unpiloted vehicles for military use. C．win a $lm jackpot. D．keep American troops unharmed.