单项选择题
Tropical cyclones are classified by form and intensity.Which system does not have closed isobars（）.
A.Hurricane B.Tropical disturbance C.Tropical depression D.Cyclone
单项选择题 The wind is（）and decreasing.
单项选择题 The strong wind will make us（）here for some days.
单项选择题 The southeast trade winds actually blow toward the（）.
