15℃、101kPa 下，1 体积水约能溶解 1 体积的二氧化碳，A 和 B 中质地较软的塑料瓶容积相等，装置的气密性良好，且充满 CO₂。将 A 的瓶盖打开，加入体积约为塑料瓶容积 1/3 的蒸馏水，迅速旋紧瓶盖后充分振荡；向 B 中也注入体积约为塑料瓶容积 1/3 的蒸馏水，充分振荡。

①A 中观察到的实验现象是____，其原因是____。

②B 中观察到的实验现象是____，其原因是____。

已知函数f（x）=$\frac{1}{3}$x³+（1﹣b）x²﹣a（b﹣3）x+b﹣2的图象过原点，且在原点处的切线斜率是﹣3，则不等式组$\left\{\begin{array}{c}x-ay\ge 0\\ x-by\ge 0\end{array}\right.$所确定的平面区域在x²+y²=4内的面积为（　　） 

观赏    欣赏

①法布尔把昆虫装进自己的衣袋，打算回家后再好好____。

②我们____了几位著名演员的表演。

举荐    推荐

③悼公只好让祁黄羊再____一位能接替他的人。

④主公让我____能替代我的人，事关国家安危，我不能不慎重。

阅读短文，然后从方框中选出可以填入文中空白处的单词

teacher   but    old    learn    with    boring     basketball    history    musician

Mr. and Mrs. Cooper are Americans. But now they are in Beijing ____ their kids. This is their first time to China.     

Mr. Cooper is a  ____. He sings very well. Mrs. Cooper is a ____. Her daughter studies at her school. Mrs. Cooper likes Beijing Opera very much. She thinks she can learn about Chinese ____ and culture. So she often goes to see Beijing opera. ____ her daughter doesn’t think so. She likes comedy , and her favorite movie is Mr. Bean. Mr. Cooper doesn’t like movies. He thinks they are____. He likes sports. His favorite sport is ____ . He likes Yao Ming very much. 

The Coopers want to go to Pingyao, Shanxi. It is an ____ and nice place. They want to take photos there. They can also____to speak Chinese. They can have a good time in China.