问题
选择题
— Jimmy never helps his mother with the housework.
— It would be _____ to say that he is lazy. [ ]
A. valuable
B. accurate
C. unfair
D. scientific
答案
答案：B
搜题请搜索小程序“爱下问搜题”
— Jimmy never helps his mother with the housework.
— It would be _____ to say that he is lazy. [ ]
A. valuable
B. accurate
C. unfair
D. scientific
答案：B
，可见轨道半径增大到2倍时，向心力减小到原来的
，可见轨道半径增大到2倍时，向心力减小到原来的