Color - blind people often find it difficult to ______ between red and green.
| A．distinguish | B．compare | C．contrast | D．distribute |
We will do it ourselves ________asking others to help.
| A．instead of | B．instead | C．but | D．however |
Have you ever noticed the house, ________ windows are always closed?
| A．where | B．which | C．when | D．whose |
I want to know when he ________ for New York tomorrow.
| A．has left | B．had left | C．is leaving | D．has been leaving |
Even on a cold day，he prefers ________out to play football ________ at home.
| A．going；rather stay | B．going；to staying |
| C．to go；rather than staying | D．to go；rather than to stay |
It was in 1969 ______ two Americans went to the moon by spaceship.
| A．that | B．before | C．when | D．Since |