【C15】A．occasionalB．frequentC．usualD．regular

A cube is a regular solid.（英译中)

I am a regular reader of this newspaper.（英译中)

A．regularB．oftenC．usualD．incidental

How often do you go swimming with your brother？A．I have no ideaB．It dependsC．As usualD．Of course

【C16】A．appointedB．limitedC．favouriteD．regular

It is clear that a（n)_____ student can understand it.A.ordinaryB.generalC.usualD.average