Official套题51托福听力Lecture 3文本题目及答案解析【雷哥托福】2018-09-21 17:22:59 发布 来源：雷哥托福 阅读量:2953
1.What does the professor mainly discuss?
A.Similarities between plant and animal defense strategies
B.The most common predators of spiders
C.A defense strategy used by some spiders
D.Chemical defenses animals use against some spiders
2.What is a key feature of the frame of the webs that golden orb weavers spin?
A.It is the only part of the web that has a golden color.
B.It cannot support the weight of most predators.
C.It can be produced only by young golden orb weavers.
D.It is made from nonsticky silk.
3.The professor discusses a spider silk chemical. In what ways do spiders limit the amount of energy they spend on producing this chemical? Choose 2 answers.
A.Spiders do not produce the chemical until they have reached a large enough size.
B.Spiders do not produce the silk that contains the chemical every day.
C.Spiders produce this chemical only when an attack is imminent.
D.Spiders produce this chemical only when attacked by a large number of predators.
4.What difference between social spiders and golden orb weavers does the professor mention?
A.Social spiders use a unique chemical to attack prey.
B.Social spiders mainly employ behavioral defenses against predators.
C.Social spiders make webs that are composed entirely of sticky threads.
D.Social spiders are not usually preyed on by ants.
5.Why does the professor mention parasitic spiders?
A.To point out that golden orb weavers prey on other spiders
B.To answer a student’s question about a type of web design
C.To clarify a point about golden orb weavers’ defense strategies
D.To identify a type of spider that uses other spiders’ webs to catch prey
6.What does the professor hypothesize on the basis of the study’s findings?
A.That other species of spiders might have defense mechanisms similar to those used by golden orb weavers
B.That golden orb weavers have more than two defense strategies against ants
C.That the chemical produced by golden orb weavers may be produced by other animals
D.That the chemical produced by golden orb weavers could be produced synthetically