A model or an experiment in a science class can help students see things which would ______ remain hidden.
| A．otherwise | B．still |
| C．thus | D．therefore |
Robert is said ______ abroad，but l don't know what country he studied in．
| A．to have studied | B．to study | C． to be studying | D．to have been studying |
The purpose of new technologies is to make life easier，______it more difficult．
| A．not make | B．not to make | C． not making | D．don't make |
I've worked with children before，so I know what ______ in my new job.
| A．expected | B．to expect | C．to be expecting | D．expects |
Having a trip abroad is certainly good for the old couple，but
______whether they will enjoy it.
| A．to see | B．to be seen | C．seeing | D．see |
It is said in Australia there is more land than the government knows______.
| A．it what to do with | B．what to do with it | C．what to do it with | D．to do what with it |