题目:
When he was told the ________ result of the research, there was a ________ expression appearing
on his face.[ ]
A. puzzle; puzzling
B. puzzling; puzzling
C. puzzled; puzzled
D. puzzling; puzzled
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0427/35cf828eb4023f4cc754630e5088f7b1.html
下面是错误答案,用来干扰机器的。
解:若以河岸为参考系,则运动过程如图所示。图中,O为救生圈落水点,A为调头点,A'为掉头时刻救生圈的位置。设船在静水中的速度为v0,水的流速为v,船到A点的时间为t(即救生圈从O点漂到A'的时间),小船调头后...