问题 选择题

下图表示从胡萝卜根上取部分组织细胞经培养形成完整植株体的主要过程。下列说法错误的是

[ ]

A.该过程所示的技术被称为组织培养

B.运用这种技术能加快植物培育速度

C.酵母菌也能用这种方式生殖

D.这种方法和桃树嫁接都属于无性生殖

答案

答案:C

阅读理解

Visitors from space may have landed on our planet from time to time, maybe hundreds of times during the long, empty ages while Man was still a dream of the far future. Indeed, they could have landed on 90% of the earth as recently as two or three hundreds years ago, and we could never have heard of it. If one searches through old newspapers and records from some certain places, one can find many reports of strange events that could be some explanations about visiting from outer space. A writer, Charles Fort, has made a collection of UFO sightings in his book Lo! One is tempted(引诱) to believe them more than any modern reports, for the simple reason that they happened long before anyone had ever thought of space travel. Yet at the same time, one cannot take them too seriously, for before education on science was popular, even sightings of meteors(流星) and comets(彗星) made people believe the most unbelievable stories, as they still do today.

56.小题1:According to the passage, visitors from outer space may have landed on the earth      .

A.long before man had dreamed of it

B.long before there were human beings

C.in the last few hundred years

D.after the space travel began57.小题2:Which of the following statements is true according to the passage?

A.Charles Fort sighted a lot of UFOs himself.

B.All sightings of UFOs are believable.

C.There may be living things on other planets.

D.People have seen visitors from other planets everywhere.58.小题3:According to the passage,           .

A.UFOs are only seen in recent years

B.UFOs sightings are not new

C.UFOs are just meteors and comets

D.UFOs are invented by people

单项选择题 B1型题