The days are gone physical strength was all you needed to make a living.
| A．when | B．that | C．where | D．which |
---I apologized for_____ to tell you when and where the meeting will be held in advance.
| A．my being not able | B．me not to be able |
| C．my not being able | D．me to be not able |
Most birds find it safe to sleep in the trees, but _____ they have eggs or young chicks, they don’t use a nest.
| A．why | B．how | C．unless | D．where |
---What were you doing when Tom came to see you?
---I had just put on my overcoat and_____ to visit my friends.
| A．left | B．was left | C．was leaving | D．had left |
As ______along the river bank, she was singing a pop song.
| A．walking | B．walked | C．to walk | D．walk |
_____ is known to everybody, Taiwan is part of China. We must unify it.
| A．It | B．As | C．That | D．What |