——Is there a bank at the first ____________?
——No, there isn't.
A:cross
B:crossing
C:crosses
D:across
控制环境污染有利于人类的生存和生物圈的稳定,下列做法有利于控制环境污染的是( )
He used to __________ in a small village, but he has been used to __________ in a big city now.
小行星绕恒星运动,恒星均匀地向四周辐射能量,质量缓慢减小,可认为小行星在绕恒星运动一周的过程中近似做圆周运动.则经过足够长的时间后,小行星运动的( )