每个装配尺寸链中至少要有3个环,其中封闭环就是要保证的装配精度或装配技术要求,故是尺寸链中最重要的环。( )
参考答案:对
With their market share shrinking, analysts ______ that their profits have fallen by around 15%.
A.accomplish
B.reckon
C.promote
D.urge
气压给水设备由( )几个基本部分组成。
A.密闭罐
B.水泵
C.换热器
D.控制器材
E.空气压缩机