He___________ his grandparents in the countryside last week．（ ）
| A． |
visits |
B． |
visit |
C． |
visited |
Mr． Black walked around and offered help____we were doing an experiment．（ ）
| A． |
while |
B． |
although |
C． |
until |
D． |
unless. |
Michael_________in a school in Yunnan from February to June next year．（ ）
| A． |
teach |
B． |
taught |
| C． |
will teach |
D． |
was teaching |
Must I do the project on my own？
No， you____．You can work with your classmates．（ ）
| A． |
needn't |
B． |
can't |
C． |
shouldn't |
D． |
mustn't |
Frank is an independent boy． His parents are proud ____ him．（ ）
| A． |
on |
B． |
to |
C． |
in |
D． |
of |
The bridge between the two islands is _______ one in Shanghai．（ ）
| A． |
long |
B． |
longer |
| C． |
longest |
D． |
the longest |