12.I rained heavily in the south, _______ serious flooding in several provinces.

A. caused           B. having caused       C. causing        D. to cause

13.My father warned me _______ going to the West Coast because it was crowed with tourists.

A. by              B. on          C. for            D. against

14.As a new graduate, he doesn’t know _______ it takes to start a business here.

A. how            B. what         C. when          D. which

15. —John went to the hospital alone.

—If he _______ me about it, I woul have gone with him.

A. should tell       B. tells         C. told           D. had told