red is a symbol of warmth, it can sometimes make people feel uneasy or even frightened.
| A．As | B．While | C．If | D．Since |
Occasions are quite rare ____ I have the time to spend a day with my kids.
| A．who | B．which | C．why | D．when |
Of the 9,500 drivers since the beginning of the year, 23% were found lacking road
knowledge.
| A．test | B．testing | C．tested | D．were tested |
It didn’t surprise us at all caused his success.
| A．why | B．that | C．how | D．what |
He called the police for help, that the problem was more than he could deal with.
| A．having been realized | B．realizing | C．realized | D．had realized |
Most of the students have hardly ever been to the Grand Canyon, __?
| A．haven’t they | B．have they | C．aren’t they | D．are they |