15. _______ all the inventions have in common is _____they have succeeded.A. What; what B. That; that C. What; that D That; what
-I'm going to San Francisco for a couple of days. -__________. I wish I could get away for a while.
-I love the Internet. I've come to know many friends on the Net. -__________. Few of them would become your real friends.
After the boy disappeared, the anxious relatives and friends spent months trying to __________ what had happened.
The orange looks dry, but you may be able to _____ a few drops.
Rod loves _____ clocks. However, he never manages to put them together again.