. The flowers now raised here have developed from those ________ in the forest.
| A．once they grew | B．they grew once | C．that once grew | D．once grew |
Walking alone in the dark, the boy whistled to his courage.
| A．hold up | B．keep up | C．set up | D．take up |
It was in the remote mountain areas I spent the gap year I learned how to work with a group of strangers and how to look after myself.
| A．where; that | B．when; that | C．where; when | D．that; where |
--- What are you busy with?
---The exhibition ____ in the city next week．
| A．held | B．will be held | C．to be held | D．being held |
---Jack can't concentrate on his study recently．
--- Yes, that might ____ why he did so badly in the last test．
| A．answer for | B．apply for | C．call for | D．account for |
I can hardly remember any occasions ____ I get caught in a traffic jam in our town．
| A．which | B．that | C．where | D．when |