问题
选择题
He is __________dogs, so he never keeps any of them at home. [ ]
A. interested in
B. afraid of
C. worried
答案
答案：B
搜题请搜索小程序“爱下问搜题”
He is __________dogs, so he never keeps any of them at home. [ ]
A. interested in
B. afraid of
C. worried
答案：B
角斜向下,如图所示,求棒MN所受的支持力大小和摩擦力大小.