The astronauts found that ______ the spaceship went further and further into space, it became more and more difficult to control its own movements.
| A．if | B．till | C．as | D．while |
I am too tired. I _____ my homework all morning.
A have been doing B did C do D have done
_____ we know, Mr. Black is an expert on language teaching.
A As B That C Which D What
–You are twenty minutes late.
--Sorry, my car _____ on my way here.
A broke up B broke off
C broke away D broke down
This milk doesn’t taste _____ this morning.
A well B nicelyC good D lovely
The letter is from my sister, _____ is working in Beijing.
A which B that C whom D who