A:had seen; was playing
B:saw; played
C:had seen; playing
D:saw; was playing
世界上最长的山脉是( )
①灰尘由于具有惯性,继续保持原来的静止状态;
②一手拿着沾有灰尘的衣服,用另一只手轻轻拍打;
③灰尘与衣服分离落向地面,衣服便干净了;
④衣服受力后运动状态发生改变,由静止运动起来.
我国在建国后首先实行“分田到户,自负盈亏”的是( )
下列词语中,没有错别字的一组是( )
Look at my s____.