题干
The flood is believed ____ more than 50 people and made thousands homeless, ____ it perhaps the most destroying flood in history in the area.
A：killing; to make
B：to have killed; making
C：to have killed; having made
D：having killed; making
答案(点此获取答案解析）
B
为定值电阻，电流表A 选用0～0.6 A量程，电压表
选用为0～3 V量程，电压表
选用为0～15 V量程，滑动变阻器
上标有“50 Ω 1A”的字样．
图线，如图(丁)所示，电源电压是