Experiments of this kind __________ in both the U. S. and Europe well before the Second World War started.
| A．have conducted |
| B．have been conducted |
| C．had conducted |
| D．had been conducted |
I don’t think those curtains _______ very well with the wallpaper.
| A．suit | B．go | C．fit | D．match |
You’d better _______ your diet rather than eat the same food all the time.
| A．vary | B．change | C．improve | D．exchange |
The book _______ forty maps, _______ that of Great Britain.
| A．contains, includes | B．is containing, including |
| C．includes, contains | D．contains, including |
I know nothing about the young lady _______ she is from Beijing.
| A．except | B．except for | C．except that | D．besides |
Scientists say it may be five or ten years _______ it is possible to test this medicine on human patients.
| A．after | B．before | C．since | D．when |