单项选择题
The inner cloud bands of a hurricane，when viewed from a distance，form a mass of dense，black cumulonimbus clouds called the（）.
A.bar of the storm B.eye of the storm C.funnel D.front
单项选择题 The greater the pressure difference between a high and a low pressure center，the（）.
单项选择题 The form of cloud often known as mackerel sky which is generally associated with fair weather is（）.
单项选择题 The fog produced by warm moist air passing over a cold surface is called（）.
