The tourists didn’t stop to rest at each station because it ______them down.
| A．had slowed | B．would slow | C．should have slowed | D．would have slowed |
— It’s the office! So you know eating is not allowed here.
— Oh, sorry.
| A．must | B．will | C．may | D．need |
It is known to all that ____ computer was invented in the USA.
A. that B. / C. the D. one
You will be late _____ you leave immediately.
| A．unless | B．when | C．while | D．as |
Don’t leave your keys in the car. Someone might steal ________ .
| A．one | B．that | C．this | D．it |
we can avoid _________ with rest and a balanced diet.
| A．ill | B．to get ill | C．getting ill | D．be ill |