The pilot is on board,（） ?

单项选择题The iron mike is a(n) （）.

A.pilot
B.speaker
C.standby wheel
D.automatic pilot

单项选择题The first indications a mariner will have of the approach of a warm front will be （）.

A.large cumulonimbus (thunderclouds) building up
B.high cirrus clouds gradually changing to cirrostratus and then to altostratus
C.fog caused by the warm air passing over the cooler water
D.low dark clouds accompanied by intermittent rain

单项选择题The characteristic of a lighted cardinal mark may be （）.

A.very quick flashing
B.flashing
C.fixed
D.occulting

单项选择题Temperature and moisture characteristics are modified in a warm or cold air mass due to （）.

A.pressure changes in the air mass
B.movement of the air mass
C.the heterogeneous nature of the air mass
D.upper level atmospheric changes

单项选择题Please wireless to let me know （） I am to anchor or to meet pilot．

A.which
B.where
C.what
D.who