—Your sister’s plan is not quite practical.Why not try to persuade her to give it up?—My sister is very stubborn,so it is________to try to change her mind.
Thanks to scientific research, we now have a good understanding of ______ an earthquake is and why it happens.
--- What shall we prepare for our picnic this weekend? --- Well, let’s discuss it ______ lunch.
How can you expect to learn anything ______ you spend all your time playing computer games?
--- How easy is it to find a taxi in this city?---Simply _______ your hand, and a taxi appears in no time.
---Would you please help me get this job with the company?---Sure. You know, I would do ______ for you.