__________ puzzles me most is that I don't know __________ the difference between the two lies.
| A．What; how | B．What; where |
| C．That; what | D．How; which |
He was very busy that day，but he seemed_________ when we dropped by．
| A．unbearable | B．skeptical | C．delighted | D．challenging |
1 would like it_______ by credit card，may I?
| A．to pay | B．pay | C．paying | D．paid |
________warmly for his excellent work，the model worker was too _______ to fall asleep．
| A．Praising；excited | B．To praise；exciting |
| C．Praised；exciting | D．Praised；excited |
_________in the traffic jam，he got to school very late this morning．
| A．Having caught | B．Catching | C．Being caught | D．Caught |
As the economy is getting better and better，there are more and more jobs _______．
| A．valuable | B．available | C．previous | D．convenient |