Some teenagers _______ their health because they often expose themselves to so many electric products.
| A．have damaged | B．are damaging | C．damaged | D．will damage |
_______ a satisfactory operation, the patient recovered from illness very quickly.
| A．Having been given | B．Having given | C．Giving | D．Being given |
.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 |