This is the first time that I _____ the summer palace．
| A．had visited | B．have visited | C．visit | D．visited |
______ is know to all, china will be an________ and powerful country in 20 or 30 year’ time.
| A．That, advancing | B．This, advanced | C．As, advanced | D．It, advanced |
When I went in , they were ____ in a heated discussion .
| A．absorb | B．absorbed | C．absorbing | D．being absorbed |
The ________ for tonight’s talk is protecting the environmet.
| A．title | B．subject | C．news | D．theme |
You can't camp________you like these days. Many natural areas are now under protection.
| A．whichever | B．wherever | C．what | D．when |
The samples__________in quality but were general acceptable．
| A．varied | B．changed | C．disagreed | D．Exchanged |