你可能感興趣的試題

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

單項(xiàng)選擇題

The characteristic of a lighted cardinal mark may be （）.

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