Most direct substitution of groups bound to an aromatic nucleus is limited to diazonium salts.大多数连于芳核能被直接取代的基团仅限于重氮盐.Severe steric effects at the reactive carbon would impede the substitution.大的立体效应阻止在碳上的取代.We use saccha...
In my experience a straight substitution of carob for chocolate doesn'twork.根据我的经验，用角豆制品直接代替巧克力行不通。We use saccharin in substitution for sugar.我们用糖精代替糖.Substitution, No.3 for No.4.换人,4号下, 3号上....
Discovery's takeoff this morning from Cape Canaveral was flawless.“发现”号航天飞机今晨从卡纳维拉尔角顺利发射升空。She attributed her flawless complexion to the moisturiser she used.她将自己无瑕的肌肤归功于所使用的保湿霜。Her English is almost flawless.她的英语几乎...
学生们分组研究复杂的问题。The students work in groups on complex problems.参加者按年龄分组。Participants were categorized according to age.你的工作是把他们按字母顺序分组，然后按数字顺序排序。Your job is to group them by letter and put them in numerical order....
These are the result of the penetration of the larvae into the crypts.这些是幼虫钻入滤泡的结果.Note the crypts that are lined by numerous goblet cells.表明腺管由很多杯状细胞排列.The villi , crypts, goblet cells and endocrine cells were presen - ...
He is clearly too partisan to be a referee.他倾向性过于明显，当不了裁判。He had unmistakably been waving his flag to attract the referee's attention.他显然一直在挥舞旗子吸引主裁判的注意。The referee has to think the way the players do.裁判必须从运动员的角度考虑问...