A:walked a crowd of young girl
B:did a crowd of young girls walk
C:were walking a crowd of young girl
D:a crowd of young girls were walking
孙亮同学参加十五米折返跑体育现场测试,共计跑了52次,下图中能分别表示该过程中他体温变化和单位时间内耗氧量变化的曲线是( )
_______ old man behind Tom is _______ university teacher.
一株苹果树的不同枝条分别结出红富士和国光两种果实,所采用的繁殖方式为( )