He looked around and caught a man __________ his hand into the pocket of a passenger.
| A．put | B．to be putting | C．putting | D．to put |
Only when I read the Frog by Moyan a second time _________ to appreciate his magic realism.
| A．did I begin | B．I began | C．had I begun | D．I have begun |
He is writing a novel, so he shuts himself up, ________ to receive guests.
| A．refuses | B．to refuse | C．refusing | D．refused |
Mr. Black is very happy because the clothes made in his factory have never been _________.
| A．popular | B．more popular | C．most popular | D．the most popular |
The Hengxin Square is located in ____________ used to be our canteen.
| A．what | B．where | C．which | D．the place |
Helping others is a habit, ________ you can learn even at an early age.
| A．it | B．that | C．what | D．one |