It’s clever _____ her to work out _____ many difficult math problems.   

A．for; so

B．of; such

C．of; so

D．for; such

头部肌肉由额肌，颞肌，皱眉肌，升降眉机，颧机，下唇方肌、眼轮匝肌、（）等组成。