多项选择题电气元件布置图在布置元器件时，发热元件应该安装在控制柜的（ ）或者（）。 A、下方 B、上方 C、后方 D、中间
不定项选择The key to reinforcement theory is that it ignores factors such as goals, expectations, and needs, and focuses solely on what happens to a person when he takes some action.
