On a working copy of a weather map，a cold front is represented by what color line? （）

单项选择题Navigational warnings and weather bulletins for shipping（）from Singapore Radio.

A.broadcast
B.broadcasted
C.are broadcast
D.are broadcasted

单项选择题NASHA VERELLA ST JACQUES ZENMU ANSHA REEF CLOUDY TO OVERCAST WITH SHOWERS WIND SW 17 TO 21 SEA MOD VIS GOOD TO MOD.The abovementioned forecast is probably from（）.

A.Radio Dalian
B.Radio Guangzhou
C.Radio Singapore
D.Radio Bangkok

单项选择题Most high pressure areas are accompanied by（）.

A.precipitation
B.clear，cool weather
C.humid，sticky weather
D.cool fogs

单项选择题MAINLY VARIABLE 3 to 4 VEERING NELY 5 TOMORROW MORNING．This forecast refers to（）in the designated area.

A.visibility
B.winds
C.sea
D.fog

单项选择题MAINLY GOOD BECOMING MODERATE.This forecast probably refers to（）in a certain area.

A.visibility
B.winds
C.sea
D.fog