垄断和垄断竞争之间的主要区别是( )。A．前者依据MR=MC最大化其利润，后者不是

车上原有乘客54人，下去28人后，又上车19人，现在车上有乘客多少人？

桃子味美可口，桃子的食用部分属于果实结构中的   [ ]

A．果皮          

B．种子          

C．果皮和种子      

D．果皮或种子

      "Everything happens for the best," my mother said whenever I was disappointed. "Don't worry. One

day your luck will change."

      I didn't pay attention to her words. After finishing my college education, I decided to look for a job

in a radio station. I wanted to host a sports programme. I went to Chicago and knocked on the door of

every station. But I got turned down every time.

     In one station, a kind lady said to me that I hadn’t got enough experience. "Get to a small station and

work for some time," she said.

     When I went back home, my dad told me that a businessman had opened a store and needed someone to help him. But again, I didn't get the job.

     I felt really down. "Your luck will change," Mum said to me. Later, I tried another radio station in Iowa. But the owner, a nice man, told me he had already had someone to work for him. As I left his office, I

asked, "How can someone be a sports announcer (播音员) if he can't get a job in a radio station?"

     I was waiting for the lift when I heard the man call, "What did you mean? Do you know anything about football?" He let me sit in front of a microphone and asked me to try to imagine that I was giving my

opinion on a football game, and finally I succeeded.

     On my way home, Mum's words came back to me, "One day your luck will change, Son."

1. What was the writer's ideal（理想的）job?

A. A sportsman.                          

B. A shop assistant.        

C. A sports announcer.                      

D. A businessman.

2. Why didn't the writer get the job in Chicago?  

A. Because he was too young.

B. Because he didn't get a college education.

C. Because he was not a good-looking person.    

D. Because he hadn't got enough experience.

3. The sentence "I got turned down every time" means "           ".

A. I was refused every time            

B. I was successful every time

C. I lost my way every time            

D. The door of every station was closed

4. The writer got a job             in the end.    

A. in Chicago                          

B. in his home town

C. in a college                            

D. in Iowa

心肌梗死后24小时内避免给予（）

A.洋地黄

B.安体舒通

C.吗啡

D.硝普钠

E.硝酸甘油

目前我国实施的结核病控制规划中，推荐的主要抗结核药物治疗方案的特点是

A．采用强化期和继续期两阶段用药，可采用间歇治疗方案，隔日顿服
B．采用强化期和继续期两阶段用药，均采用每日疗法，采用顿服方式
C．采用强化期和继续期两阶段用药，广泛采用间歇治疗方案，采用每日3次用药的方式
D．采用强化期和继续期两阶段用药，均采用每日疗法，采用每日3次用药的方式
E．采用强化期和继续期两阶段用药，广泛采用间歇治疗方案，采用每日2次口服的方式