By nine o’clock, all the Olympic torch bearers had reached the top of Mount Qomolangma, _________ appeared a rare rainbow soon.
A. of which B. on which C. from which D. above which
Do you know since when it is ________ you have been interested in poetry?
A. when B. until C. how D. that
What’s the __________ of having a public open space where you can’t eat, drink or even simply hang out for a while?
A. sense B. matter C. case D. opinion
It is worth considering what makes “convenience” foods so popular, and_______ better ones of your own.
A. introduces B. to introduce C. introducing D. introduced
Whose possession has the house _________ since the 1500s?
A. taken B. been taken C. been in D. come into
The findings of the research, _________ on a lot of experiments, are convincing.
A. to base B. based C. is based D. basing
