特别注意分析句子的结构才能辨别谓语与非谓语。
①The traffic rule says young children under the age of four and __ less than 40 pounds must be in a child safety seat.
A. being weighed B. weighs C. weighed D. weighing
【解析】容易误选B或C，将其当成谓语看待。under the age of four and ____ less than 40 pounds用作children的定语。动词weigh与名词children是主动关系，所以选择weighing。
