A:If
B:Whether
C:Before
D:How
以下对四个实验的认识,正确的是( )
You should tell _____ about it if _____ doesn't know it.
按要求写出本课学过的字词。
①与水有关的字:____ ____ ____
②与嘴有关的字:____ ____
He never ____learning English .That was why he was successful at last.