The teacher _______some old friends on his vacation trip to Paris.
| A．dropped by | B．dropped in | C．droped by | D．droped in |
All the doctors and nurses in this hospital ______ the patients.
A. go on with B. are patient with C. keep up with
To keep away from germs, we must not spit ______.
A. in danger B. in need C. in public
The river has become much ______ than before because of the waste water from the factories.
A. dirty B. dirtier C. dirtiest
In China, spring returns in March. The weather ______ warm and the days are longer.
A. gets B. sounds C. smells
A computer ______ think for itself. It’s always told to do things.
A. mustn’t B. can’t C. shouldn’t