There happened to be nobody under the wall when it fell down, ____ ?
Remember, at any given moment, you are in __________ with one per-son and one person only-yourself.
Without the contribution of Qian Xuesen, China __________ such great achievements in space technology.
Unfortunately, many people were buried __________ in the earthquake which happened in Taiwan just a few days ago.
__________ well prepared you are, you still need a lot of luck in finding a suitable job.
When asked about their opinions about the school master, many teachers would prefer to see him step aside __________ younger men.