【C7】A．toB．inC．onD．toward

The policemen were told to be alert（) the dangers they were facing.A toB inC onD at

Computers can be designed ______ many automation processes purposes.A．toB．inC．onD．for

A．toB．inC．onD．for

【C7】A．according toB．related toC．based onD．because of

【C8】A．toB．withC．onD．as

【C9】A．toB．withC．onD．as