罗茨]鼓风机叶轮的齿廓与直齿圆柱齿的廓完全相同。
参考答案:错
Mary three of her classmates invited to the party.
A.as well; has been
B.and; have
C.as well as;was
D.as good as; were
玉米在()缺磷表现明显。
A、抽穗期
B、苗期
C、成熟期
D、花芽分化期