I don't know when he back．Please tell me when he back．（ ）
| A． |
comes，comes |
| B． |
comes，will come |
| C． |
will come，comes |
The environment here becomes better and better． birds are coming back．（ ）
| A． |
Hundred |
B． |
Hundreds |
| C． |
Thousand |
D． |
Thousands of |
More trees every year to make our city greener．（ ）
| A． |
is planted |
B． |
are planted |
| C． |
was planted |
D． |
were planted |
To avoid making mistakes， please read the questions before you answer them．（ ）
| A． |
careful |
B． |
careless |
C． |
carefully |
D． |
carelessly |
Hong Kong is __ the south of China， it's one of the busiest cities in the word．（ ）
| A． |
in |
B． |
on |
C． |
at |
D． |
to |
My sister practices playing ___ piano for the coming talent show．（ ）
| A． |
a |
B． |
an |
C． |
the |
D． |
/ |