爆笑英语口语 第75期:知根知底

 Language Points

God only knows.

If you know what is good for you

know backwards¹ and forwards=know inside out

He's been teaching physics for 30years,so he knows the subject backwards and forwards.

1 backwards   

adv.往回地，向原处，倒，相反，前后倒置地

参考例句：

• He turned on the light and began to pace backwards and forwards.他打开电灯并开始走来走去。
• All the girls fell over backwards to get the party ready.姑娘们迫不及待地为聚会做准备。