28. Be careful! The slightest spark（火花）could ______ the fireworks.
| A．set about | B．set off | C．set out | D．set up |
Some of the students have already learned enough English to _______a conversation with an English speaker.
| A．go on (vi.) | B．carry on (vt. Vi.) | C．keep on | D．hold on |
—Is there anything wrong, Bob? You look sad.
—Oh, nothing much. In fact, I __________ of my friends back home.
| A．have just thought | B．was just thinking |
| C．would just think | D．will just be thinking |
The newspaper's owner and editor ___ away on holiday.
| A．is | B．are | C．be | D．have been |
Rose’s humor was________ make every student burst into_______.
| A．so amused as to…laughter | B．so amusing as to… laughter |
| C．such that…laughing | D．so that… laughing |
If you see Jack please give my __________ to him for not having written to him.
| A．apology | B．excuse | C．message | D．theory |