填空

（1）1平角=______直角一周角=______直角 1周角=______平角

（2）89^○的角是______角，89^○的2倍是______角．170^○的角的一半是______角，70^○的2倍的角是______角

（3）45^○角和______度角的和是直角，45^○角和______度角的和是平角．

（4）30^○角的______倍是直角，30^○角的______倍是平角，30^○角的______倍是周角．

Frank, with his two sisters, ________ London by train which ________at 8:30 next morning.

A．is leaving for; will leave

B．are leaving for; leaves

C．is leaving for; leaves

D．will leave for; will leave