A. My father often reads books on Sundays.
B. I often do my homework on Saturdays.
C. He often watches TV in his room.
D. We often play football on the playground.
E. Ann can wash her clothes by herself.
如图所示,已知足球放在桌子上,而桌子立于地球表面.下列两个力是一对平衡力的是( )
下列各句中,没有语病的一句是 ( )
原子中决定元素种类的粒子是 ( )
读某地气温和降水逐月分布图,回答问题。该地7、8月份气温最高,降水量6月最多,该地区是( )