(2013·安徽，21)From space, the earth looks blue. This is ________ about seventyone percent of its surface is covered by water.
| A．why | B．how |
| C．because | D．whether |
The village I grew up ____ has changed a lot.
| A．in it | B．in | C．in that | D．in which |
We went to Canada to travel and my cousin ___ as our guide.
| A．played | B．showed | C．acted | D．performed |
Gun control is a subject ___ Americans have argued for a long time.
| A．of which | B．with which | C．about which | D．into which |
——How about your new school?
——I couldn’t feel _____ about it. All my teachers are very kind and helpful.
| A．better | B．worse | C．best | D．worst |
He is the only one of the people here who ____ how to operate the computer.
| A．knows | B．know | C．had known | D．known |