There are _____ to show that Rome will win the bid to host the 2020 Olympic Games.

A. signals     B. marks     C. signs      D. symbols

There are ______ to show that a new , different city is coming out of its dark past .

    A. signals   B. marks      C. signs       D. symbols

　　One of New York's most beautiful and valuable building　　 1_________

is in danger. The New York Public Library, in the　　 2_________

heart of the city at 42 Street may have to close its　　　　 3_________

doors. The library is very special place. Even though　　　　4_________

it is in a busiest part of the city, it has grass　　　　 5_________

and trees around it, and benches for people to sit.　　　　 6_________

Even more unusual in the crowding New York, its rooms　　 7_________

are very large. The roof of the Main Reading Room are　　 8_________

fifty-one feet tall. Here, a reader can sit and think and　　9_________

work comfortable. And what books there are to work with! 10_________

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
It’s summertime-time once again for mosquitoes to make their appearance. And once they appear, mosquitoes are a total pain. They land on you,  bite you, suck out some blood and leave behind an itchy welt（发痒的红肿）.
  1  Female mosquitoes must find blood in order to reproduce, so mosquitoes come equipped with finely tuned sensors to help them locate the blood they need.
Mosquitoes’ weapons
Mosquitoes have perfected three different types of sensors. First, mosquitoes can sense several different chemicals. Mosquitoes can smell carbon dioxide and lactic acid（乳酸）up to 100 feet away.   2 
Second, mosquitoes have very good eyesight. If you are wearing clothing that contrasts with the background, and if you move while wearing that clothing, mosquitoes can see you. It’s a good bet that anything moving is alive, and therefore full of blood.
Finally, mosquitoes come equipped with temperature sensors, so they can find warm-blood mammals and birds very easily.
  3  The female mosquito sticks her proboscis（喙）into you. She sucks about five microliters of your blood into her abdomen.
After she has bitten you, some saliva（唾液）remains in the wound.   4  The area swells and you tich. Eventually, the selling goes away, but the itch remains until your immune cells break down the saliva proteins.
Our defense methods
Because mosquitoes are both a nuisance（讨厌的东西） and a danger, people prefer to stay away from mosquitoes. One way to do that is to use a chemical called DEET, which seems to black a mosquito’s chemical sensors.   5  In some cities there are even trucks that drive around town to spray for mosquitoes. Finally there are to traps. The most popular traps turn propane（丙烷） into carbon dioxide and warmth to attract mosquitoes. Over time, by catching large numbers of mosquitoes, these traps can cause the collapse of the mosquito population in the area.

There are________to show that a new, different city is coming out of its dark past.

A. signals             B. marks             C. signs               D. symbols