The book was written in 1946, _________the education system has witnessed great changes.
A. when B. during which
C. since then D. since when
Those successful deaf dancers think that dancing is an activity____sight matters more than hearing．
A. when B. whose
C. which D. where
We shouldn't spent our money testing so many people, most of_________are healthy.
A. that B. which
C .what D. whom
It is reported that two schools,_____are being built in my hometown, will open next year.
A. they both B. which both
C. both of them D. both of which
____is often the case, we have worked out the production plan.
A. Which B. When
C. What D. As
____I explained on the phone, your request will be considered at the next meeting.
A. When B. After
C. As D. Since
