By age 7 months, an infant most likely will develop which of the following motor skill

A. Walk with one hand held.
B. Eat successfully with a spoon.
C. Stand while holding onto furniture.
D. Sit alone using the hands for support.

效标是衡量测评结果有效性的参照标准、效标可分为（）

A、合同效标

B、观念效标

C、标准效标

D、行为效标

E、思想效标