Experiments of this kind ________ in both the U.S. and Europe long before the Second World War.
| A．conducted | B．was conducted |
| C．had been conducted | D．had conducted |
All foreign visitors are requested to _____ with the regulations in this area.
| A．agree | B．comply | C．consent | D．conform |
These continual _____ in temperature make it impossible to decide what to wear.
| A．alterations | B．vibrations | C．waves | D．fluctuations |
The illness from which Mary is suffering has now been _____ as hepatitis (肝炎).
| A．diagnosed | B．determined | C．deduced | D．discovered |
A completely new situation is likely to _____ when the school leaving age is raised to 16.
| A．arouse | B．rise | C．arise | D．abide |
I must go now. _____, if you want that book I'll bring it next time.
| A．Incidentally | B．Accidentally |
| C．Occasionally | D．Subsequently |