A:S = 2
B:S = 4
C:S = 8
D:S = 1
看图列式。
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给划线的字选择正确的读音。
说话____ (shuō shuì) 说笑____ (shuō shuì) 游说____ (shuō shuì) 说一不二____ (shuō shuì)
This pair of jeans______ hand, and it______ very comfortable.
脊椎动物和无脊椎动物主要区别在于( )