—Where did you find our chemistry teacher? —It was in the lab ______ he was doing his experiment.
9._____ makes this shop different is that it offers more personal services.
8.Although this_______ sound like a simple task, great care is needed.
7.Please ______ your sister to bring the ticket for the concert.
6.Be careful! The slightest spark(火花)could ______ the fireworks.
5.The police are offering a $ 60,000 _____ for information about the killer.