The earth is the planet _______ provides us with everything we need，fresh air，clean water and so on．It's our duty to protect it．（ ）
| A． |
who |
B． |
that |
C． |
where |
Who is the man in black over there？
Mr. Smith． He teaches math．（ ）
| A． |
we |
B． |
our |
C． |
us |
D． |
ourselves |
Would you mind turning down the music？ I'm trying to solve the math problem．
． I'll do it in a second．（ ）
| A． |
Sure |
| B． |
Of course not |
| C． |
That sounds impossible |
| D． |
Never mind |
When I want to go out to play with my friends， my mother always says，"_____ at home．Don't waste your time．"（ ）
| A． |
Stay |
B． |
Stays |
C． |
To stay |
D． |
Staying. |
As the most exciting and traditional way to shop， street markets _____ here and there in China these days．（ ）
| A． |
find |
B． |
found |
C． |
are found |
D． |
were found |
Let's go camping if it _____ next Saturday．
But nobody knows if it_____．（ ）
| A． |
is fine； rains |
| B． |
will be fine； rains |
| C． |
is fine； will rain |
| D． |
will be fine； will rain |