I can hardly imagine Peter ______ across the Atlantic Ocean in five days.
| A．sail | B．sailing | C．to sail | D．to have sailed |
Teachers have to constantly update their knowledge in order to maintain their professional ___.
| A．consequence |
| B．independence |
| C．competence |
| D．intelligence |
Though told to stop, the excited speaker ___ talking.
| A．tried on |
| B．kept up |
| C．kept on |
| D．went up |
He thought he heard someone following him, and ___ round. He caught sight of a dark figure in the shadow.
| A．glanced |
| B．glared |
| C．stared |
| D．observed |
What does it matter whether you are rich or poor, ___ you are happy.
| A．as long as |
| B．unless |
| C．even if |
| D．though |
She wondered how it ___ that her husband met with trouble again.
| A．came up |
| B．came across |
| C．came out |
| D．came about |