小题1: The Blacks love__________(游泳), and they are all good at it.

小题2:At __________(周末), Tom and his family often go to the park.

小题3: Her grandma often remembers the old and the __________(贫穷的) in her prayers（祈祷）.

小题4:There are a lot of __________(现代化的) cities in America.

小题5:. —May I __________(借) your ruler, please?

—Sure. Here you are.

不能用来区别CO和CO₂两种气体的方法是 [ ]

A. 通入澄清的石灰水

B. 观察气体的颜色

C. 通入紫色石蕊试液

D. 点燃气体