Most of the earth's surface ______ by water．（ ）
| A． |
is covered |
B． |
covers |
C． |
is grown |
D． |
grows |
Mr．Smith knows a lot about China he has never been to our country．（ ）
| A． |
although |
B． |
until |
C． |
if |
D． |
since |
Rainy days make me relaxed．I love drinking tea while it ．（ ）
| A． |
was raining |
B． |
is raining |
| C． |
has rained |
D． |
rained |
The dictionary belong to Sam．You can see his name on it．（ ）
| A． |
can |
B． |
must |
C． |
need |
D． |
would |
Nelson exercises because he has too much work every day．（ ）
| A． |
usually |
B． |
always |
C． |
often |
D． |
seldom |
Humans can not make progress dreams．（ ）
| A． |
with |
B． |
without |
C． |
through |
D． |
about |