The train due to _______ at 10 am was delayed for 2 hours because of the storm.
A.arriving B.arrive C.be arriving D.having arrived
—Have you finished the book?
—No，I’ve read up to____ the children discover the secret cave.
A.which B.what C.that D.where
Among the crises that face humans ________ the lack of natural resources.
A.is B.are C.is there D.are there
He asked them to come to his office one ________.
A.at no time B.at one time C.at a time D.in no time
In the global economy, a new drug for cancer, ________ it is discovered, will create many economic possibilities around the world.
A.whatever B.whoever
C.wherever D.whichever
________our manager objects to Tom's joining the club，we shall accept him as a member.
A.Until B.Unless C.If D.After
