Smoking, ____ some smokers, might ease their anxiety sometimes, but ____ the addiction caused by their constant practice, it is really hard to give up.

Scientists _______ a lot of experiments on animals, hoping to find and effective way to cure the patients who had AIDS.

When seeing the snake, she       a scream.

Don’t worry. Intelligent students can always ­­­­­­­­­_______ good solutions to problems.

I __________ Wang Ping again and flew after him.