【2015·重庆】We must find out ____ Karl is coming, so we can book a room for him.
The weather turned out to be very good,________ was more than we could expect.
Is this the factory ________ he worked ten years ago?
Alice received an invitation from her boss,________ came as a surprise.
I have bought two ballpens,________ writes well.
Is ________ some German friends visited last week?