Have you ever wondered __________ you can feel the wind but cannot see it?
A. why B. how
C. what D. whether
In times of trouble or difficulty, one may take __________ help is available.
A. whoever B. however
C. whatever D. wherever
—Have you heard any news about Sarah?
—Yes, she was promoted to president of her company, __________surprised everyone.
A. who B. that
C. which D. it
We were grateful to Mr. Marks, in __________ car we had travelled home on the rainy night.
A. which B. whom
C. that D. whose
—Did you enjoy your trip?
—Yes. But for your advice, we __________ our stay in London half as much.
A. didn’t enjoy B. hadn’t enjoyed
C. wouldn’t enjoy D. wouldn’t have enjoyed
Going camping in the desert will not be enjoyable __________ you are well prepared.
A. because B. when
C. unless D. until
