课程咨询

托福考试网 托福资料下载 托福资讯 0元讲座 水平测试

托福考试练习
新东方在线 > TOEFL > 托福阅读 > 正文
托福培训

扫码免费领资料

内含托福全科备考资料

更有免费水平测试及备考规划

托福培训

扫码关注掌握一手留学资讯

回复XDF免费水平测试

录播精讲 直播课HOT

托福阅读词汇题：sustained

2015-08-26 15:35:29来源：网络

　　【托福阅读题型：sustained词汇题】托福阅读中词汇题是重要题型之一。根据托福阅读题型不同来进行专项练习，是短期提高托福阅读能力的有效方法。同学们需要多加练习哦!

　　查看全部：托福阅读题型分类练习之词汇题

　　托福阅读词汇题：sustained

　　【Paragraph 3】Animals need natural periodic signals like sunrise to maintain a cycle whose period is precisely 24　hours. Such an external cue not only coordinates an animal's daily rhythms with particular features of the local solar　day but also—because it normally does so day after day-seems to keep the internal clock's period close to that of　Earth's rotation. Yet despite this synchronization of the period of the internal cycle, the animal's timer itself continues to　have its own genetically built-in period close to, but different from, 24 hours. Without the external cue, the difference　accumulates and so the internally regulated activities of the biological day drift continuously, like the tides, in relation to　the solar day. This drift has been studied extensively in many animals and in biological activities ranging from the　hatching of fruit fly eggs to wheel running by squirrels. Light has a predominating influence in setting the clock. Even a　fifteen-minute burst of light in otherwise sustained darkness can reset an animal's circadian rhythm. Normally, internalrhythms are kept in step by regular environmental cycles. For instance, if a homing pigeon is to navigate with its Sun　　compass, its clock must be properly set by cues provided by the daylight/darkness cycle.(Biological Clocks)

　　The word “it” in the passage refers to

　　○ an external cue such as sunrise

　　○ the daily rhythm of an animal

　　○ the local solar day

　　○ a cycle whose period is precisely 24 hours

　　The word “sustained” in the passage is closest in meaning to

　　○ intense

　　○ uninterrupted

　　○ natural

　　○ periodic

　　答案见下一页：

本文关键字: 托福阅读题型 托福阅读训练 词汇题

上一页 1 2 下一页

托福辅导

关注新东方在线托福

托福机经·Official题目练习

考前重点突破·听说读写海量资料

更多资料

关注新东方在线托福，
回复【XDF】获取大礼包

托福辅导
  • 1.打开手机微信【扫一扫】，识别上方二维码；
  • 2.点击【添加】，回复对应关键字领取学习资料。
更多>>
更多内容

免费获取托福备考大礼包

微信扫描下方二维码 立即领取

托福辅导
更多>>
更多公益讲座>>
更多>>
更多资料
托福TPO 托福听力练习 托福口语练习 托福阅读练习 托福写作练习
我要
反馈 返回
首页
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10