The mistake on the locally printed postage stamps was in the ______.

B) colour

C) carelessness

D) inscription

what did she do in Gull Lake Biological Station？

She worked as_____

where did she get her B． S degree from？

She got her B． S degree from________

According to the passage, the southern part of the Yunnan-Guizhou Plateau_____.

B) is hot in the day and cold in the night

C) is cold in winter but hot in summer

D) is neither very hot nor very cold

Stamp collectors have paid $16,800 for ______.

B) twelve Two Penny Blues

C) one One Penny Orange-Red

D) fourteen One Penny Orange-Reds

How much does a user pay if he has broadband technology installed？

B) It depends on the times of dial-up.

C) He pays at a fixed monthly rate.

D) He pays a lot of money.