__ we are young, we can still do something to help protect the environment.

A．If                B．Since             C．Because          D．Though

This dress still looks beautiful on her _____ it is last year’s style.

A．because          B．though            C．if                D．since

—When are you going to fly to Taiwan this summer?

—_________ we finish school. It will be a great holiday.

A．Because          B．Since             C．Even though       D．Only if