如图所示,一束光照射到平面镜上,请画出其反射光线.
-Qin Shu has just beaten Li Hui in our school ping-pong game!
-It's hard to _________ a girl with only one arm can play ping-pong so well!
观察漫画,简要回答。
科技人员用高产倒伏小麦和低产抗倒伏小麦培育出高产抗倒伏小麦,这说明( )