I don’t think _________ possible to master a foreign language without much memory work.
| A．this | B．that | C．it | D．its |
The truth, Sir, is that the old man____ across the street when my car hit him.
| A．was to walk | B．had been walking | C．walked | D．was walking |
---Where will you start your work after graduation?
---Mmm, it's not been decided yet. I ____ continue my study for a higher degree.
| A．need | B．must | C．would | D．might |
I wrote to my parents once a week,____ I was too busy with my teaching work.
| A．it | B．unless | C．when | D．as |
However, at times this balance in nature is disturbed, ____ a number of possibly unforeseen effects.
| A．lying in | B．calling in | C．taking in | D．resulting in |
--- He has to finish the experiment today. He must be in the lab,____?
---That s quite possible.
| A．mustn't he | B．won't he | C．doesn't he | D．isn't he |