某地区从1964年开始使用杀虫剂杀灭蚊子幼虫，至1967年中期停用。_爱下问搜题

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问题填空题案例分析题

某地区从1964年开始使用杀虫剂杀灭蚊子幼虫，至1967年中期停用。下图是五年间蚊子幼虫基因型频率变化曲线。R表示杀虫剂抗性基因，S表示野生敏感型基因。据图回答：

1969年中期RR基因型几近消失，表明在（）的环境条件下，RR基因型幼虫比SS基因型幼虫的生存适应能力（）（高、低）。

答案

参考答案：不再使用杀虫剂；低

完形填空

Do you like travelling? Today, I’ll give you some about travelling. You should have a good night’s sleep you travel. If you don’t, you will feel tired he way. You should take some with you. It may be helpful when you feel sick. You should have a meal before travelling. If you eat anything, you’ll feel hungry. And the food on the train is much more .You should listen to the weather report earlier, so you can a good plan for your travel. You’d better take a(n) with you. It can keep off the sun and the rain. You should your right clothes when you prepare your luggage(行李). If you’re going from a hot place to a cold place, you have to some warm clothes. You should drink enough water. Don’t wait to be . You’d better take some water you can have a drink when you want to drink. You should write down all the travel : departure(出发) and arrival time, bus or train number, your parents’ names , address and phone number and so on. You should take a . You can take lots of photos when you see beautiful scenery. When you come back, you can show the pictures to your friends. Above all, yourself when you are travelling. But please look after yourself and your things carefully.

A．in order to

C．information

单项选择题

调制箍围药，取其清凉解毒作用的，应选用

A．醋

B．葱

C．鸡蛋清

D．麻油

E．丝瓜叶汁