51.In the author’s eyes, Elvis Presley was _________.
A. disgusting B. admirable C. ambitious D. dynamic
52. From the passage, we can know that _________.
A. Buster Brown was more appealing than Elvis Presley
B. An Elvis hair cut cost the orphans a lot of money
C. The author was fascinated with the stars Buster and Elvis
D. The barber was unwilling to give the boy an Elvis hair cut
53. We can learn from the underlined sentence that the boy was _________.
A. excited to have an Elvis hair cut
B. worried to think about the secret
C. anxious to remove the ton of bricks
D. careful to seize the chance
54. How would the boy probably feel when he walked out of the barber shop?
A. Delighted. B. Guilty. C. Self-satisfied. D. Depressed.
B
Talking plants might sound like characters in a fairy tale. But recent scientific studies have shown that plants communicate with each other and with other living things in a surprising number of ways. To understand them, scientists say, we just have to learn their language. Farmers are especially interested in what plants have to say.
“Plants are able to communicate with all sorts of organisms (有机体). They can communicate with giant bacteria, with other plants and with insects. They do this chemically,” said Cahill, an Ecology Professor of the University of Alberta in Canada.
Plant scientists are just beginning to understand this chemical “ language”. Cahill says studies have shown, for example, that plants can evaluate conditions in their immediate environment and take appropriate actions. Plants have an ability, for example, to signal pain or discomfort caused by anything from temperature extremes to an insect attack. Jack Schultz, a professor of chemical ecology at the University of Missouri, says when a plant senses that it’s being eaten, it cannot walk away from trouble; on the contrary, it will release a chemical vapor that alerts other plants nearby.
“Their language is a chemical language, and it involves chemicals that move through the air that are easy to be changeable, and most of all are smells that we are familiar with,” Schultz explained.
“All plants responded to the attack by changing their chemistry to defend themselves,” Schultz recalled. “But we were quite surprised to find that nearby plants also changed their chemistry to defend themselves, even though they were not part of the experiment.”
Studies have also shown that plants under attack release pleasant chemicals. Those chemicals attract friendly insects that attack the pests eating the plant.
In the end, plants’ ability to communicate their needs---and our ability to understand them--- could help farmers reduce the use of poisonous chemicals, cut operating costs and limit damage to the environment.
55. The recent scientific studies have shown that plants can _________.
A. communicate with other living things in a chemical way