为什么This machine is___metal.填made of而不填make of

This machine is unavailable. This book is__(good）of the four books. This coffee shop is__(open)around the clock This is__(I)in the class.请问怎么填呀? This is__(I)in the class.请问怎么填呀? Those three problems are all__,but this one is__.(difficult) 为什么This machine is___metal.填made of而不填make of There is something wrong with this machine.It needs repairing.请问为什么要用”repairing” The coaches are practicing how to use this machine.为什么how后面要用to, I can`t understand the sentence,because the meaning of this verb is__?A obviouse ,B obscurewhy?可是为什么答案给的是 A？这点我不能理解 1.That pencil box is___(she) 2.This is his book.The book is__(he) 3.Is this ruler___(Sally)?4.This pen is__(you).that pen is__(i)5.The white pencil is__(my). WE will give you a machine that works .We will exchange this one .将We will exchange this one.提到句首后变为了We will exchange this one for a machine that works.为什么要用for? This kind of machine can p_______ music. This machine is very easy to This machine is very easy to the machine has been recovered this This machine is very easy to__.A.use B.be use为什么选A.机器不是被用吗,应该是被动啊? This is his own car改为同义句:This car is__ __