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 |
suggestion
| A．information | B．question | C．exhibition | D．connection |
nature
| A．camera | B．labor | C．village | D．natural |
The doctor did __________ save the patient’s life.
| A．that he could do | B．all what he could |
| C．all he could to | D．which he could |
—Tom, have you finished your homework?
—Yes, I ________ before you came back, mom.
| A．finished | B．have finished | C．had finished | D．finish |
I wonder why you didn’t do as ________ and it’s the third time you have done this.
| A．telling | B．be told | C．told to | D．tell |