She couldn't help laughing when she heard the humorous story.
A:funny
B:boring
C:short
线段AB=10cm,BC=5cm,A、B、C三点在同一条直线上,则AC=____
如图所示是一种声光报警器电路,各元件均能正常工作。下列现象描述正确的是 ()
一分硬币是圆柱体.