Jack did nothing but ___.
| A．complain | B．to complain | C．complained | D．in complaining |
The students all wear the same uniform,so it’s hard for me to ________my son among them.
| A．bring out | B．pick out | C．pick up | D．break out. |
Not recognizing me at first, __________.
| A．he closed the door | B．the door was closed |
| C．the door was close | D．I closed the door |
She was always _____ , even when things were at their worst.
| A．attractive | B．optimistic | C．pessimistic | D．frightened |
This also keeps the air，soil，water crops________ chemicals.
| A．out of | B．out from | C．free of | D．rid of |
____polite to others and you can get friendship in turn.
| A．Be | B．To be | C．Being | D．/ |