下图表示暖锋天气的示意图是 （ ）
答案：A
暖锋是暖气团主动向冷气团方向移动，暖气团沿冷气团徐徐爬升，暖气团势力强，冷气团被迫后退
It's common knowledge that black tea ________ in China more than 600 years ago.[ ]
A. is invented
B. was invented
C. invents
D. invented
热痉挛主要是由于哪个方面的障碍所致
A．心血管B．神经C．消化D．体温调节E．水盐代谢
