对尺寸要求较高的产品的模具，其导向机构主要有（）。
A.导柱导向
B.锥面定位导向
C.导柱导向和锥面定位导向
D.导滑槽
参考答案：C
___ recent report stated that the number of Spanish speakers in the US would be higher than
that of English speakers by ___ year 2090. [ ]
A. The; a
B. A; /
C. The; /
D. A; the
揉中脘、摩腹，分腹阴阳之法的作用是（）
A.祛风散寒
B.健脾和胃
C.解表清热
D.理气消食
E.理肠止泻
