正确合理的选择，使用和保养量具，是每个机械工人都应掌握的（）
A.一门技术
B.根本技术
C.基本技术
D.特殊技术
参考答案：C
The teacher, with 6 girls and 8 boys of her class, ____visiting a museum when the earthquake struck [ ]
A. was
B. were
C. had been
D. would be
