There are fifty p____ in my class.
①都诞生于公元以前 ②都诞生于亚洲
③最后都为统治者所利用 ④它们的传播有利于各地区间文化交流
She has a long tail. 的意思是:她有一条长尾巴。
—My mother is nice to all her students. And she gets on well with all her friends.
根据匀速直线运动的速度公式v=st可知( )