Cathy said she speak four languages.[ ]
A. may
B. could
C. would
D. can
答案:B
随月经周期而有周而复始变化的是( )
A.致密层B.海绵层C.基底层D.海绵层与基底层E.海绵层与致密层
混凝土构架模板支撑搭设跨度超过()是属于高大模板支撑系统。
A、8m
B、12m
C、16m
D、18m