题目

氨基酸形成肽链过程中会失去水分子（H20），失去的水分子（H20）中的氢元素来自  A.羧基                                    B.氨基   C.羧基和氨基                              D.H2O和氨基 答案：C　　Mr Robinson had to travel somewhere on business, and as he was in a hurry, he decided to go 1 . He liked sitting 2 a window when he was flying, so when he got onto the plane, he looked for a window seat. He 3 all of them taken except one. There was a young man 4 beside it and Robinson was surprised that he had not taken the one 5 the window. Anyhow, he went towards it. 　　When he 6 it, however, he saw that there was a notice on it, written 7 large letters, 8 “This seat is kept for proper balance. Thank you.” Mr Robinson had never seen such a notice before, but he thought the plane 9 something particularly heavy in its room 10 made it necessary to have the passengers properly 11 . So he walked on and found 12 empty seat, not beside the window 13 . 　　Two or three other people 14 to sit in the window seat 15 the young man, but they also read the notice and went on. Then when the plane was nearly 16 a very beautiful girl 17 into the plane. The young man, who was watching the passengers coming in, 18 took the notice 19 the seat beside him and 20 succeeded in having a pretty companion during the whole trip. 1． [　　] A．by airB．by water C．by trainD．by bus 2． [　　] A．onB．nearly C．besideD．far from 3． [　　] A．wantedB．found C．thoughtD．hoped 4． [　　] A．seatingB．seated C．was seatedD．sat 5． [　　] A．withB．had C．byD．in 6． [　　] A．arrivedB．sat on C．reachedD．left 7． [　　] A．throughB．by C．withD．in 8． [　　] A．saidB．saying C．spokenD．speaking 9． [　　] A．must be carryingB．must carry C．must have carriedD．must be 10． [　　] A．andB．this C．whoD．which 11． [　　] A．terrifiedB．interested C．pleasedD．balanced 12． [　　] A．anotherB．other C．the otherD．the only 13． [　　] A．to sitB．to be sat C．to sit onD．to be sat in 14． [　　] A．stuckB．tried C．managedD．refused 15． [　　] A．beforeB．after C．aboveD．next to 16． [　　] A．emptyB．full C．upD．down 17． [　　] A．reachedB．stepped C．enteredD．left 18． [　　] A．quicklyB．fast C．slowlyD．soon 19． [　　] A．ontoB．away C．offD．up 20． [　　] A．by this meansB．in a way C．by the wayD．on the way