_____ the flight to Beijing will be delayed is _______ I’m especially worried about.
| A．If; what | B．Whether; that | C．When; that | D．Whether; what |
A poet and artist ______ coming to speak to us about Chinese literature and painting tomorrow afternoon.
| A．is | B．are | C．was | D．Were |
Generally, there may be several different ______ to the same issue.
| A．methods | B．means | C．approaches | D．ways |
We can give you a lift to the airport _______ you don’t mind the crowdedness, for there have already been four of us in the car.
| A．unless | B．though | C．provided | D．until |
Being a teacher, you must observe your behavior, for ________ you say and do has a life-long effect on your students.
| A．that | B．which | C．what | D．as |
He made another wonderful discovery, _______ of great importance to science.
| A．which I think is | B．which I think it |
| C．which I think it is | D．I think which is |