_____ these experiments were successfully completed would we think of
going into humans.
| A．If only | B．So that | C．Only if | D．Even if |
Jackson has got to be crazy ________Chinese culture since he visited China last time.
| A．about | B．with | C．for | D．at |
He has three brothers, ________is a doctor.
| A．all of them | B．all of who |
| C．none of whom | D．both of them |
___________ catch the early bus, he got up very early this morning.
| A．In order to | B．So that |
| C．So as to | D．In order that |
Our school was ________ in 1925 and has a history of more than 80 years.
| A．set up | B．set off |
| C．set out | D．found |
________ stopping polluting the earth ________ hope to live in a better environment.
| A．Only to; we can | B．Only to; can we |
| C．Only by; can we | D．Only by; we can |