单项选择题
In North America the majority of the weather systems move from（）.
A.north to south B.south to north C.east to west D.west to east
单项选择题 In bad weather，what length of chain should be used with a single anchor? （）
单项选择题 In a storm，the leeward lines of a ship’s mooring system will（）.
单项选择题 If you are caught in the left semicircle of a tropical storm，in the Southern Hemisphere，you should bring the wind（）.
