当外界负荷突然增大时，锅炉水位将（）。
A、下降
B、上升
C、先下降后上升
D、先上升后下降
参考答案：D
____ through Africa, the infectious disease jumping from children to adults killed 1,000 people.
A．Swept
B．Having been swept
C．Having swept
D．Sweeping
简述传感器静特性的概念？
