③和④两大洲的分界线( )
A.白令海峡
B.苏伊士运河
C.巴拿马运河
D.乌拉尔山脉
读图可知,③是北美洲,④是南美洲,北美洲与南美洲的分界线是巴拿马运河.
故选:C.
— What do you think of the lecture made yesterday?
— Excellent! _______ you missed such a wonderful lecture?[ ]
A. How is it that
B. Why it was that
C. How was it that
D. When was it that
通常把萝卜腌成咸菜需要几十天,而把萝卜炒成熟菜,使之有相同的咸味,只需几分钟,造成这种判别的主要原因是( )
A.盐的分子很小,容易进入萝卜中
B.盐分子有相互作用的斥力
C.萝卜分子间有空隙,易扩散
D.炒菜时温度高,分子热运动激烈