_____,allmachinesarecombinationsofsimplerpartssuchasthelever,thepulley,andtheinclinedplane.
A.However complicated are they B.However difficult they are C.Whether they are old or new D.No matter how complex they are正确答案D
_____,allmachinesarecombinationsofsimplerpartssuchasthelever,thepulley,andtheinclinedplane.
A.However complicated are they B.However difficult they are C.Whether they are old or new D.No matter how complex they are正确答案D