Question

Our teacher insisted that the key words worth paying attention _______ before class.

1. A.
   be underlined　
2. B.
   being underlined
3. C.
   to be underlined　
4. D.
   to being underlined

Answer 1

C
考查虚拟语气。to是与pay attention连在一块的；(should)be underlined是insist的虚拟语气，故选C。