语法填空 (共10小题，每小题1.5分，满分15分)
阅读下面短文，按照句子结构的语法性和上下
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空，并将答案填写在答题卡标号为31～40的相应位置上。
Mosquitoes are very small insects. There are more than two thousand different kinds of mosquitoes. Female mosquitoes bite people  31  (drink) their blood. Male mosquitoes do not drink blood. They drink liquids from plants.
The female mosquito uses its long thin sucking tube to break the skin and find blood. The insect injects the victim with a substance（物质） 32  keeps blood flowing.
The female mosquito drinks the blood and uses  33  to produce eggs. One meal gives her enough blood to produce as many as two hundred fifty eggs. The mosquito  34  (lay) them in any standing water.
The eggs produce worm-like creatures in two days to a few months. However, some eggs can stay in water for years  35  conditions are right for development. The worm-like creatures feed  36  organisms in the water. After four to ten days, they change again, into creatures  37  (call) pupas (蛹). The pupas rise to the surface of the water. Adult mosquitoes pull themselves out of the pupas  38  fly away.
The World Health Organization says mosquitoes cause disease and death for millions of people  39  the world. That is because mosquitoes can carry organisms that cause disease.  40 , the disease does not affect mosquitoes.