What ______ public is concerned about is whether medical workers and scientists will be able to find for this new disease in a short time.
| A．不填;不填 | B．不填;the | C．the;不填 | D．the;a |
Factory workers have to work very hard, and _________.
| A．farmers do so | B．farmers work so |
| C．so have farmers | D．so do farmers |
Only when David did it a second time _________.
| A．he realized his mistake |
| B．he was realizing his mistake |
| C．did he realize his mistake |
| D．he did realize his mistake |
So instructive _________ that the student wanted to see it again.
A. was the film B. it was the film
C, the film was D. the film it was
Not until I went to America _________ what kind of country it was.
| A．did I know | B．I did know |
| C．I didn't know | D．I could know |
_________ forget my hometown and my happy childhood.
| A．Never I will | B．Never will 1 |
| C．Never I | D．I never have |