can、it、do、is、will这一类是什么词?

...,do you?...,can ...will you?...shall it? you can do it ,you will make we can do it!I will do it !是什么意思? I must do it !I can do it !I will do it !什么意思 I Belive the dream will come ture I can do it you can do it —Do you think it will do us good or ____(harm)?其中good在这是什么词, I will do it.I can do it.(合并成含it条件的省略句) What is this?how old is it?do you like it?can it swim?can it IF I CAN I WILL DO IT WELL! can _______swim______skate.Will you teach me how to do it? It is a circle.It is bumpy.You can play with it.这是什么? It is unnecessary to think we can do nothing about it这句话该怎么翻