问题 问答题 简答题

简述二圃制与三圃制原种生产程序及异同点。

答案

参考答案:

程序:

二圃制:单株选择、株行圃、原种圃。

三圃制:单株选择、株行圃、株系圃、原种圃。

相同点:都是按照单株选择、混系比较、混系繁殖。

不同点:一个是三年三圃,一个是两年两圃,前者提纯复壮的程度高,后者则纯度较低。

单项选择题
阅读理解

Michael Jackson, the American pop legend, died of a cardiac arrest(心脏骤停) in a Los Angeles hospital last night, just weeks before he hoped to resurrect(复活) his four-decade long career with a series of sold-out shows in London. The pop superstar was taken to the University of California at Los Angeles medical centre last night, and doctors tried resuscitation(使苏醒,使复活) in the ambulance. He did not regain consciousness and was reported dead about three hours later.

"My brother, the legendary King of Pop, passed away on Thursday 25 June at 2.26pm," his brother Jermaine said, "We believe he suffered a cardiac arrest at his home, however the cause of his death is unknown until the results of the autopsy(验尸) are known. The personal physician who was with him at the time attempted to resuscitated him."

A spokesman for the UCLA medical centre said, "When he arrived at hospital at approximately 1.14pm, a team of doctors attempted to resuscitate him for a period of more than one hour, they were unsuccessful." Police said they were investigating, which is standard procedure in such cases.

Jackson's death brought a tragic end to a long decline from his peak in the 1980s when he was music's greatest all-around performer, a uniter of black and white music who shattered the race barrier on MTV. His 1982 album Thriller, which included the blockbuster hits Beat It, Billie Jean and Thriller is still the best-selling album of all time, with an estimated 50m copies sold worldwide.

The world famous entertainer had planned a series of 50 concerts in London from 12 July. Although in the last two decades his reputation was destroyed by charges of child molestation(骚扰) and his fantastic public behavior, all tickets were sold within hours, proving the King of Pop had enduring appeal.

49.   Where did Michael Jackson die?

A. At home in Los Angeles.                 B. In a Los Angeles hospital.

C. On the stage in London.                  D. In an ambulance to hospital.

50. What caused Michael Jackson to die according to Jermaine?

A. Heart disease.                        B. It’s unknown before the results of the autopsy.

C. Working too hard.                         D. His personal physician’s improper treatment.

51. Why were the police involved in investigating the death of Michael Jackson?

A. Because they believed he was murdered.

B. Because it was standard procedure in such cases.

C. Because Michael Jackson died suddenly.

D. Because his brother was suspicious of the truth of his death.

52. It can be inferred that Michael Jackson was ___________.

A. a King of Pop with good reputation.

B. a King of Pop still playing on the stage before death.

C. indeed a bad man with fantastic public behavior.

D. a popular King of Pop in spite of ill fame.