The drug used to treat this disease causes bad side effects, some of which ________ deadly.

Three months ________ since we met last time.

Every student as well as teachers who ______ to visit the museum ______ asked to be at the school gate on time.

Mike and I             good friends.

When the headteacher announced his plan for a spring outing，the ______ of the students in the class ______ for it.