Being a female tree is hard. A study of a species that can change sex has revealed that most striped maple trees die while fem

admin2021-12-24  11

问题   Being a female tree is hard. A study of a species that can change sex has revealed that most striped maple trees die while female.
  "We had a suspicion they were changing sex, which is relatively rare among plants." says Jemnifer Blake-Mahmud at Princeton University. Between 2014 and 2017, she and Lena Struwe at Rutgers University in New Jersey observed the life cycles of 457 striped maples in New Jersey, recording their health, diameter and whether they had female or male flowers each spring.
  They found that 54 percent of the trees changed sex during that time, and one fourth of those did so at least twice. A model based on these findings showed that, contrary to previous suggestions, healthy trees were more likely to be male and a tree’s size doesn’t influence its sex.
  The growth rate of trees that remained female for many years declined. Of the trees that died, 75 percent had recently produced female flowers. "It’s remarkable," says Blake-Mahmud. "When I see a tree that’s dead and I look back in my datasheet, it was almost always female the year before."
  It isn’t clear why this is the case. It could be that female trees need more nutrients because they produce seeds, and it may increase the death rate of female trees, she says.
  But it could also be that dying trees become female as a last effort to create offspring and pass their genes on to the next generation.
  "These populations have a lot more male trees than female trees in general, so just by luck, a female has a better chance of being a parent of the next generation than a male," says Blake-Mahmud. "If you’re going to die anyway, then being female is the way to go. That would make more evolutionary sense."
The word "declined"(Line 1,Para.4) is closest in meaning to_________.

选项 A、got worse
B、died away
C、went down
D、wore out

答案C

解析 本题为词义猜测题。根据题目我们定位到第四段的第一句“The growth rate of trees that remained female for many years declined.”(保持雌性数年的树的生长速度开始下降),decline的主语为The growth rate(生长速度),即使不知道单词本意,考生需要联系选项选择符合原文本意的单词:A.got worse“变坏”;B.died away“逐渐消失”;C. went down“下降”;D.wore out“用坏;穿破;(使)筋疲力尽;耗尽”。在选项中,只有C更为搭配。而decline与increase是反义词,表示下降。故正确答案为C。
转载请注明原文地址:https://kaotiyun.com/show/4yRC777K
本试题收录于: 英语题库普高专升本分类
0

最新回复(0)