下面关于脑血管病的预防描述正确的是（）

A.主要包括一级预防和二级预防

B.一级预防是针对具有脑血管病危险因素的人群开展预防工作

C.一级预防主要是控制和治疗危险因素

D.二级预防是针对发生过脑血管病的患者开展预防工作

E.二级预防主要是在控制和治疗危险因素的基础上，进行针对性治疗

I got a job teaching special education at a school in Coachella, California, a desert town about 170 miles from home. It was no (1) job. Street gangs (2) around the school after dark."Be careful," Dad warned me during one of my frequent weekend (3) home. He was concerned about my living (4) , but I needed to be on my own.One evening, I stayed after school to rearrange my classroom. (5) , I turned out the light and closed the door. Then I (6) toward the gate. It was (7) ! I looked around. Everyone had gone home.After (8) all the exits, I found just enough (9) to squeeze under a gate in the back of the school. Then I walked toward my car, parked in a field behind the building.Suddenly I heard voices. I (10) around and saw at least eight boys following me. (11) my pace, I reached into my shoulder bag to get my key. I (12) all over the inside of my handbag. But the key wasn’t (13) ! Dear Lord, please help me, I prayed (14) . Suddenly, my fingers touched a loose key in my purse. I didn’t even know if it was for my car, but I took it out and (15) it. It worked!I opened the door, slid in and locked it—just (16) the teenagers surrounded the car. Trembling , I started the engine and (17) away. When I returned to my apartment, the phone was ringing. It was my Dad. I didn’t tell him about my experience; I didn’t want to (18) him. "Oh, I forgot to tell you!" He said, "I had a(n) (19) car key made and slipped it into your purse—just (20) you ever need it.

第（1）空应选择（）

A．dream

B．difficult

C．exciting

D．heavy