1993年，我国科学家将苏云金杆菌中的抗虫基因转入棉花植株，培育出抗虫的转基因棉

鲸的呼吸器官是 [ ]

A．肺

B．鳃

C．气管

D．皮肤

A: What’s the date today

B: It’s June 16.

A: (1) Then it’s the Dragon Boat Festival today, isn’t it

B: Yes. (2)

A: Did you have rice dumplings this morning

B: Sure. (3)

A: I didn’t.

B: What a pity! But I happen to have got some with me. (4)

A: I’d love to. By the way, why do you call it the Dragon Boat Festival

B: Because in China, people race dragon boats this day every year.

A: Oh, I see. (5)

B: You are welcom

A. We Chinese usually eat rice dumplings this day.

B. I hate eating rice dumplings.

C. Thank you for your rice dumplings.

D. I don’t think so.

E. Would you like to have one

F. Already

G. How about you

第（2）空应选择（）

下图是某市近郊农田近几年两栖动物青蛙的数量统计数，请思考回答下列问题：

(1)从1988年到2000年，由于环境等因素的影响，青蛙的数量减少了一半，请你分析这些环境因素是什么？(至少答出两条)

(2)青蛙是农田害虫的天敌，为减少杀虫剂对人类健康的影响，请你帮助农民朋友制定保护青蛙的措施。(至少答出两条)

诊断急性呼吸窘迫综合征的必要条件是（）

A.血氧饱和度

B.动脉血氧分压

C.氧含量

D.氧合指数

E.肺泡-动脉氧分压差

活动是幼儿了解环境的主要方式。