Which is a traffic sign? 

—Could you tell us _________ to do it?—Of course. First of all, you should clean the wall, then clean the floor.

–  Bad luck! The car breaks down again. I wish I knew about car repair.________ you learn? Courses are offered at Seamine College.________. I wonder when courses begin.

(2013·济南3月模拟)—I failed my driving test.—________；they say the best drivers always fail the first time.

—Hello, Tony , nice to meet you!—___________________!