7岁以前儿童的短时记忆容量也为7±2个信息单位。 ( )
参考答案:错
Throwing their hats into the air, the fans of the winning team _____ loud shouts of victory.
A.let down
B.let in
C.let go
D.let out
标示牌根据其用途可分为()等。
A.警告类
B.允许类
C.提示类
D.禁止类