下列关于茧形成的说法,正确的是( )
A:家蚕的幼虫吐出蚕丝,结成茧
B:家蚕的成虫吐出蚕丝,结成茧
C:家蚕的卵吐出蚕丝,结成茧
D:家蚕的蛹吐出蚕丝,结成茧
下列食物成分中,不能为人体提供能量的是( )
⑴Where is the eraser? ____
⑵Where are the crayons? ____
⑶Put your book on your desk. ____
A.OK!
B.It's under your pencil box.
C.They're in my hand.