I cleaned my room yesterday． It _______ a little difficult．（ ）
A．isB．wasC．will be
The lights is on．When you leave，please _____．
OK，I won't forget ____it．（ ）
| A． |
turn it off； to do |
| B． |
turn off it； doing |
| C． |
turn on it； to do |
It takes me half an hour _____playing the piano．How about you？
I usually spend 20 minutes ____it．（ ）
| A． |
practicing； on |
| B． |
to practice； in |
| C． |
to practice； on |
Someone is knocking at the door，Is it Tom？
It _____him．He has gone to Beijing．（ ）
| A． |
may not be |
B． |
can't be |
C． |
mustn't be |
The weather in Qiqihar is colder than ____in Shanghai．（ ）
| A． |
those |
B． |
it |
C． |
that |
WeChat（微信） is widely used．_____the young _____the old are interested in it．
| A． |
Either； or |
| B． |
Neither； nor |
| C． |
Not only； but also |