.—Jack had a lot of parties recently.—Yes. That might ________ why he did so badly in the last test.
Leave your key with a neighbor _____you lock yourself out one day.
It was two weeks before the Spring Festival and the shopping centre was _____ with shoppers.
Many students go to school _______ the tube in Beijing every day.
Stop making noise, _______ the neighbors will start complaining.
-- How was your life in the countryside? -- It was _______ but sometimes I felt a bit _______.