When the passengers’ (乘客) families heard the bad news, they were _____ to stay calm.
—Can you play soccer? —Sorry,I ________.
Lee can play ________ piano.He can join the music club.
— ________ club do you want to ________?—The sports club.
There were some cases ______ women employees were fired when they were pregnant.
The teacher spoke of some writers and some books ________ we need to know.