When _________ where he had put the book, he kept silent.
| A．ask | B．asking | C．to ask | D．asked |
. Please remain __________ until the plane has come to a complete stop.
| A．to seat | B．to be seated |
| C．seating | D．seated |
. “Things __________ never come again!” I couldn’t help talking to myself.
| A．lost | B．losing |
| C．to lost | D．have lost |
. Jenny hopes that Mr. Smith will suggest a good way to have her written English __________ in a short period.
| A．improved | B．improving |
| C．to improve | D．improve |
. — Did Peter fix the computer himself?
— He __________, because he doesn’t know much about computers.
| A．has it fixed | B．had fixed it |
| C．had it fixed | D．fixed it |
. John received an invitation to dinner, and with his work __________, he gladly accepted it.
| A．finished | B．finishing |
| C．having finished | D．was finished |