Textbooks for junior students ______ for free in most areas of China.
A. provide B. provided C. are provided
Mom was cooking ________ Dad was reading newspapers.
| A．as | B．when |
| C．while | D．since |
---How many students have visited the West Lake? ---________.
| A．No one | B．Nothing |
| C．None | D．Nobody |
When I was in the USA,I had difficulty ______ English, so I often ask Paul ____ help.
| A．to understand, with | B．understanding, for |
| C．to understand, for | D．understanding, with |
The river is too wide for the swimmers _______________.
| A．to swim | B．to swim in |
| C．to swim across | D．swimming |
I don’t know ______ with this problem. It’s too hard.
| A．which to do | B．when to do |
| C．what to do | D．how to do |