My friend asked me to play ____ volleyball, but I’m tired and I don’t think I’ve got ____ energy.
We all need knowledge from the past — ______ it comes from personal experience or from studying history. It is our only guide to the future.
The patient has tried quite a few kinds of medicine, but ______ had any effect on his disease.
I wouldn’t eat potatoes unless I’m really starving, in _______ case you eat almost anything.
One of the consequences of our planet’s being warming up is a(n) ______ in the number of natural disasters.
World Expo 2010 Shanghai China, a grand-scale global event, has ______ the significant theme “Better City, Better Life.”