Passage Four

　　No matter who you are or where you come from, one thing is certain：you are acquainted with the mosquito(蚊子)--although you probably wish you weren’t. Mosquitoes are everywhere. They can be found all over the world, and they come in more than 2,500 species. Somewhere, at some time, you have surely met at least one.

　　No one loves the mosquito. But unfortunately the mosquito may decide that she loves you. Yes, She. Only the female mosquito bites. It’s not because she’s unfriendly: she needs blood to reproduce. Female mosquito is quite selective, and she chooses her victims carefully. First, she uses sensors to find her victim. With these sensors, she tests your body moisture, body warmth, and chemical substances in your sweat. If she likes what she finds, she bites. But if you don’t appeal to her, she’ll reject you for someone more appetizing. The next time a mosquito bites you, just remember that you were chosen. You’re special.

　　If the mosquito likes you, she settles onto your flesh very gently, and she breaks your skin with her proboscis tip. It’s a kind of mouth and it sticks out just below the mosquito’s eyes. She stabs the proboscis tip into your skin at once, and if she hits a blood vessel, she’ll get a full dinner in about a minute. After that, the mosquito is tired. Heavy with your blood, she picks a spot---on a leave or a stone---to lay her eggs. Just one drop of blood will produce hundreds of eggs.

　　31. By the sentence “you are acquainted with the mosquito--although you probably wish you weren’t”, the author means that people _________.

　　A. don’t like mosquito but it is always there

　　B. know mosquito and wish them well

　　C. wish all the mosquito disappeared

　　D. want to be friendly to mosquito but fail at last

　　32. Why is it only female mosquito that bites?

　　A. She is more unfriendly than male.

　　B. She is greater in number.

　　C. Blood is her favorite food.

　　D. Blood enables her to lay eggs.

　　33. To select whom to bite, the mosquito’s sensors may NOT test_________.

　　A. the temperature of the body

　　B. the color of the skin

　　C. the chemical elements in sweat

　　D. the wetness of the body

　　34. According to the last paragraph, the function of proboscis tip is to _______.

　　A. find where to bite

　　B. to stick into the flesh and suck blood

　　C. to remove the skin and collect blood

　　D. decide whom to reject

　　35. The main idea of the passage could be _______.

　　A. why and how mosquito bites people

　　B. why people dislike mosquito

　　C. what kind of mosquito bites people

　　D. how to identify female mosquito