. ___________ anything about the accident, he went to work as usual..
| A．Not known | B．Known not | C．Knowing not | D．Not knowing |
When I try to understand ________ that prevents so many children from being happy, there seem to be three causes.
| A．why it is | B．what it does | C．why it does | D．what it is |
—What’s wrong with my computer, Jack?
—Let me have a check. OK, it works now.
—You mean, nothing wrong with it, ________ ?
| A．is there | B．isn’t there | C．is it | D．isn’t it |
The dentist gave me a shot which took ________ almost immediately and I didn't feel a thing.
| A．offense | B．charge | C．action | D．effect |
International situation is currently undergoing great changes ________ UNESCO plays an irreplaceable role in promoting international cooperation.
| A．which | B．what | C．where | D．that |
--When were the soldiers sent to the earthquake-stricken area?
-- _______ the earthquake broke out.
| A．Shortly | B．Unfortunately | C．Straight | D．Directly |