A:all of them wore
B:all wearing
C:all of whom wearing
D:all were wearing
用铜、铝、铁制成的三个质量相等的空心球,比较它们的体积,则( )
三角形有3个角,用剪刀剪去一个角,剩下的图形一定不会只有( )个角.
根据提示写单词。