无色透明或类白色半透明，暴露空气中则表面逐渐风化而覆盖一层白色粉末的药材是
A．石膏 B．赭石 C．芒硝 D．自然铜 E．雄黄
参考答案：C
When the headmaster announced his plan in public at the school's opening ceremony, the ________
of the students present________ against it. [ ]
A. majority; were
B. most; were
C. most; did
D. majority; did
如何进行更换配电变压器跌落式熔断器（保险）熔丝（保险丝）工作？
