This machine needs _____ once a year in order to work properly.A、to checkB、checkingC、checkD、checked

There is something wrong with this machine.It needs repairing.请问为什么要用”repairing” This machine needs _____ once a year in order to work properly.A、to checkB、checkingC、checkD、checked This machine is unavailable. 1.This shirt is .(对括号内容提问） _ _ _ this shirt?2.Howmuch is the book?(同义句转换)_ _ _ _ the book?3.Tim needs a pair of sports shoes.(同义句转换）Tim needs _ _ a pair of sports shoes.4.Can I help you?(同义句转换)_ _ I _ f This plant needs( )water This friengship needs some This firendship needs some This firendship needs some work 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 I need to repair his computer=His computer needs _ _ _=His computer needs _ Machine Machine Machine This is a very expensive machine同义句转换This is( ) ( ) ( ）machine This room needs to clean.用法对么?