They said good-bye, little knowing that they _______ again.
| A．were never met | B．will never meet |
| C．never met | D．were never to meet |
.When I came in, I saw Dr. Li _______ a patient.
| A．examine | B．examining | C．to examine | D．examined |
.The cars _______ in Beijing are as good as those _______ in Shanghai.
| A．produce, produce | B．produced, produced |
| C．produced, producing | D．producing, producing |
The graduating students are busy _______ material for their reports.
| A．collect | B．to collect | C．collected | D．collecting |
I had to shout to make myself _______ above the noise.
| A．heard | B．hearing | C．heard | D．to hear |
.He walked down the hills, _______ softly to himself.
| A．sing | B．singing | C．sung | D．to sing |