(8) On the other hand, there are three reasons why scientists cannot guess all of the problems or all of the solutions. 

(9) The first reason is that they have never been successful in taming a wild plant. 

(10) The second reason is that scientists have kept records for a relatively short time. 

(11) The third reason is that each plant species is unique, different from all other plants. 

(12) The jojoba is an example of a plant that scientists are trying to domesticate.

Question 6: What words are being repeated in the four sentences above (8-12)? Write a shortened version on the basis of these changes.

15) On its many woody branches, the jojoba produces a fruit that is 40 per cent to 60 percent liquid wax.

 (16) This liquid substance, called jojoba oil, is valuable.

 (17) It can be used as a base for all kinds of cosmetics. 

(18) It works well as an ingredient in high-quality machine oils. 

(19) By domesticating the jojoba, scientists hope to change unproductive desert land into productive agricultural land.

Question 7: Read the five sentences above (15-19) and find the common elements in these sentences.

Summary B

Paragraph 2 Sentence (2 & 3) The jojoba, a wild desert bush that grows in some parts of the United States and Mexico, is about 2 metres high. (3) Its fruit is 40-60 per cent liquid wax, called jojoba oil, which is valuable.

Summary C

Paragraph 2 Sentence (2) It is a wild desert bush found in some parts of the United States and Mexico, which has fruit consisting largely of liquid wax.

Question: What are the changes that are made here?

Yet most of the plants that are important to people were domesticated, or tamed, in pre-historic times. 

For example, before history was written, corn and wheat became part of people's diets. 

People have grown these grains as crops in small fields for thousands of years.

Question: Underline or write down the words in the above sentences which say the same thing.

Summary B

Paragraph 1Sentence (2) Most of the plants that are important to people, for example corn and wheat, were domesticated in pre-historic times yet records of the domestication of plants are very recent. 

Summary C

Paragraph 1Sentence (2) Most of the important plants, e.g., corn and wheat, were domesticated in pre-historic times, but scientists are still trying to domesticate more plants.

Question: What changes has been introduced in the second sentence of Summary C to make it different from Summary B?