A. 正确 B. 错误
A. darkening,growing in size and forming an anvil top B. that shows extensive vertical development C. creating cold downdrafts that are felt on the ground D. All of the above
A. 上提管柱 B. 下放管柱 C. 旋转管柱 D. 投递工具
A. 气候 B. 平均气温 C. 平均温度 D. 平均湿度