More than one person ____ made the suggestion. [ ]
A. was
B. has
C. were
D. have
答案:B
超高分产品粘均分子量≥19×106粘度≥50mPa.s过滤因子≤1.5中分产品粘均分子量为()×106,粘度≥40mPa.s。
A、12~16
B、12~19
C、≥19
D、≥12
不允许将模样分开,必须作成整体,可采用()造型。
A.挖砂
B.活块
C.多箱