— Hello, I ____ to ask if I can book two tickets for tonight's film.

— sorry, we've already sold out.[ ]

A. phone

B. will phone

C. am phoning

D. have phoned

若在转向点附近有岛屿、浅滩等危险物，则必须在用（）或（）定位并确认有安全正横距后，才能用航迹舵自动转向。

A.NNSS，GPS

B.LORAN-C，DECCA

C.RADAR，LF（陆标）

D.TNS，SFRm