1. Rainforests are being cut and burned from Brazil to Indonesia at such a rate that they could well disappear from the earth's surface before the year 2050.
“are being cut and burned”是现在进行时被动语态。如:
1) The problem is being discussed now. (这个问题现在正在讨论。)
2)The car is being repaired by Mr. Smith. (那辆车正由史密斯先生修理。)
“at such a rate that” (以这样的速度(砍伐、焚烧)以致于…)。我们曾讲过程度副词such和so的区别。一般来说,such的后面接名词,而so的后面接形容词或副词。如:
1) He spoke for such a long time that people began to feel bored. (他讲了那么长时间,人们开始觉得厌烦了。)
2) He made such a rapid progress that both his teachers and his parents were happy.
(他取得了飞快的进步,他的老师和父母都觉得高兴。)
3) It was such a fine day that we decided to go for a walk. (天气这样好,我们打算去散步。)
4) The work was so difficult that I couldn't finish it in 2 hours. (这项工作太难,两小时内我完不成。)
5) She spoke so fast that I could catch her. (她讲话太快,我没听懂他的意思。)
“they could well disappear” 他们很可能消失。well在本句中的意思是“很可能的,很”。如:
1) It might well turn out true. (这很可能会成为真的。)
2) It's well worth trying. (这很值得一试。)
3) He must be well over forty. (他很可能大大超过四十岁了。)
2. They are being cleared for valuable timber and other resources to speed up the economic growth of the nations in which they are located.
本句中的clear用作动词,意思是remove (清除),如:
1) Brazil's forests were being cleared at the rate of almost 7,000 square miles a year.
(巴西的森林以每年近7,000平方英里的速度被清除。)
2)The children were helping me clear weeds from the garden. (孩子们在帮助我清除花园里的杂草。)
speed up是个常用短语,意思是increase the speed
1)Tom speeded up and overtook his classmates. (汤姆加快了速度,赶上他的同学们。)
1) They are determined to tap their potential to the full. (他们决心充分挖掘自己的潜力。)
2) The aim of this advertisement is to attract potential customers. (这则广告的目标是吸引潜在的顾客。)
3) You have to know more about the potential demand of the market.
(你得对市场上可能达到的需求量有更多的了解。)
5. In today's pharmaceutical market 15 of the 125 drugs derived from plants were discovered in the rainforest. derived from plants是现在分词短语做定语,相当于被动语态的定语从句。如:
1) The beer bought from the supermarket is very light. (在超市买的那啤酒口味很淡。)
2) The candy made from cactus tastes strange. (用仙人掌做的糖果味道很怪。)
15 of the 125意思是125中的15.再如two of the three (三个中的两个)
derive from意思是get from, obtain from, 如:
1) Much of his knowledge is derived from books. (他的许多知识得自书本。)
2) He derived his stories from his experiences in the countryside. (他的故事来自于他在农村的经历。)
6. Rare birds and animals that cannot be found anywhere else in the world have been disappearing at the rate of one a year since the turn of the century.
句中的else是形容词,常接在不定代词的后面,表示“其他的,别的”,如:
1) Is there anything else I can do for you?(我还能为你做些别的事吗?)
2) Did anybody else know this? (有其他人知道这件事吗?)
3) He didn't go anywhere else. (他没去其他地方。)
one a year意思是“每年一种”。这种表达方式在英语中很常用,如:
1) Take the medicine three times a day. (每日三次服这种药。)
2) They met three times a week. (他们每周见三次。)
3) He finishes 5 books a month. (他一个月读完五本书。)
当时间状语用since引导时,句子中的时态常用完成时。如:
1) He has been living here since he came to Nanjing 5 years ago. (自从他五年前来到南京,他就一直住在这儿。)
2) They haven't seen each other since last May. (自去年五月起,他们一直没见过面。)
turn在句中做名词,意思是“转折点”。since the turn of the century意思是“自本世纪初(或上世纪末)。”
1) He hasn't written home since the turn of the year. (自去年底以来他还未给家里写过信。)
2) At the turn of the two centuries, they had many hearty wishes for their family.(在两个世纪交替之时,他们对家人有许多衷心的祝愿。)