电子配料秤工作时，由（）个称重传感器做秤体的支承点。
A.2
B.3
C.4
D.1
参考答案：B
— Li Lei did very well in the English exam.
— Oh, yeah! He is ______ English. [ ]
A. weak in
B. angry with
C. good at
D. afraid of
调度员尽力维护各子系统发电、用电平衡时属（）
A.正常状态
B.紧急状态
C.恢复状态
D.瓦解状态
