new sat词眼题.ppt

词眼题 所谓词眼题其实是属于细节题的一种，这种题目标志是用引号“....”引出某个词或者词组来询问用这个词或者词眼来暗示一些什么信息。 例如.the authors use the word “backbone” in line 3 and line 39 to indicate that ....... 应对策略：根据这个引号内的词或者词组所传达的意思作为主要根据。 line3 “the molecule is a very long chain, the backbone of which consists of a regular alternation of sugar and phosphate groups.” line39 “ the phosphate-sugar backbone of our model is completely regular, but any sequence of the pairs..... the authors use the word “backbone” in line 3 and line 39 to indicate that ....... A only very long chains of DNA can be taken from an organism with a spinal column. B the main structure of a chain in a DNA molecule is composed of repeating units. C a chain in a DNA molecule consists entirely of phosphate groups or of sugars. D notrogenous bases from the main structural unit of DNA “backbone”意思是支柱，对应选项中的“main”的意思，只剩下b,d两个选项，再看下line3或者line39，可看出选b b based on the passage, the authors statement “if a pair consisted of two purines, for example, there are would not be room for it.”line29-30 implies that a pair A of purines would be larger than the space between a sugar and a phosphate group B of purines would be larger than a pair consisting of a purine and a pyrimidine c of pyrimidines would be larger than a pair of purines d consisting of a purine and pyrimidine would be larger than a pair of pyrimidines D the authors use of the words “exact” “specific” “complement” in line47-49 in the final paragraph functions mainly to A confirm that the nucleotide sequences are known for most molecules of DNA B counter the claim that the sequences of nases along a chain can occur in any order C support the claim that the phosphate-sugar backbone of the authors model is completely regular. D emphasize how one chain of DNA may serve as a template to be copied during DNA replication. if the actual order of the bases on one of the pair of chains were given, one could write down the exact order of the bases on the other one,because of the specific pairing. thus one ch