A:{x=2y=−1
B:{x=−1y=2
C:{x=−2y=1
D:{x=1y=−2
将正确的图片和句子配对
① It's yellow. It's small. It goes “Peep,peep”.
② It's fat. It goes “Oink… oink”.
③ It's big. It goes “ Moo…moo”.
④ It's thin. It's in the tree.
⑤ It's yellow. It goes “ Quack …quack”.
____ ____ ____ ____ ____
气体从外界进入人体血液的路径是____。