Are you pleased with what he has done?— It couldn’t be ________. He must have put a lot of effort into his work.

When I was in trouble, my friends often ___ me a lot of help.

This kind of virus _______ via the bloodstream and causes ill health in a variety of organs.

e President Hu Jintao paid________ visit to the Shanghai World Expo Park on Thursday, two days ahead of ________­opening of the global event

Sometimes,regret is a normal, ____response to a failure when you could have done better.[ ]