Look! How _________ the market is!—Yes. There are always lots of people buying things there.

_____ any other species, human populations are shaped by the usual forces of natural selection, like famine, disease or climate[ ]

many trials and failures, the farmer＿＿built a homemade plane that successfully got off the ground.

She his number in the phone book to make sure that she had got it right.[ ]

g about his success, the famous scientistsaid, “I’ve been lucky ______ there are many people who have helped me”.