问题 填空题

在平行四边形ABCD中,DE⊥AB于E,DF⊥BC于F,且∠EDF=60°,则平行四边形ABCD中∠A的度数是______.

答案

∵DE⊥AB,DF⊥BC,

∴∠DEB=∠DFB=90°,

∵∠EDF+∠DEB+∠B+∠DFB=360°,∠EDF=60°,

∴∠B=120°,

∵四边形ABCD是平行四边形,

∴ADBC,

∴∠A+∠B=180°,

∴∠A=60°.

故答案为:60°.

单项选择题

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.

8()

A.checking 

B.searching 

C.trying 

D.following

名词解释