具有双颞孔的动物是()。
A.鱼类
B.鸟类
C.龟鳖类
D.哺乳类
参考答案:A
He _____ you as soon as he _____ back. [ ]
A. will call; comes
B. call; comes
C. will call; will come
D. call; comes
失去标签的三瓶无色液体,分别是稀H2SO4、蒸馏水、NaOH溶液,能把它们一次性区分开的物质是( )
A.酚酞
B.铁片
C.石蕊溶液
D.二氧化碳气体