a substance's solid is higher than the density of its liquid. 大多数物质遇冷收缩,所以他们的密度在固态时高于液态 大多数物质遇冷收缩 所以他们的密度在固态时高于液态. 所以他们的密度在固态时高于液态 25. the mechanism by which brain cells store memories is not clearly understood. 大脑细胞储存记忆的机理并不为人明白. 大脑细胞储存记忆的机理并不为人明白 26. by the middle of the twentieth century, painters and sculptors in the united states had begun to exert a great worldwide influence over art. 到了二十一世纪中叶,美国画家和雕塑家开始在世界范围内对艺术产生重大影响. 到了二十一世纪中叶 美国画家和雕塑家开始在世界范围内对艺术产生重大影响 美国画家和雕塑家开始在世界范围内对艺术产生重大影响 27. in the eastern part of new jersey lies the city of elizabeth, a major shipping and manufacturing center. 伊丽莎白市,一个重要的航运和制造业中心 坐落于新泽西州的东部 伊丽莎白市 一个重要的航运和制造业中心,坐落于新泽西州的东部 一个重要的航运和制造业中心 坐落于新泽西州的东部. 28. elizabeth blackwell, the first woman medical doctor in the united states, founded the new york infirmary, an institution that has always had a completely female medical staff. elizabeth blackwell,美国第一个女医生 创建了员工一直为女性纽约诊所 美国第一个女医生,创建了员工一直为女性纽约诊所 美国第一个女医生 创建了员工一直为女性纽约诊所. 29. alexander graham bell once told his family that he would rather be remembered as a teacher of the deaf than as the inventor of the telephone. alexander graham bell曾告诉家人 他更愿意让后人记住他是聋子的老师 而非电话的发 曾告诉家人,他更愿意让后人记住他是聋子的老师 曾告诉家人 他更愿意让后人记住他是聋子的老师,而非电话的发 明者. 明者 30. because its leaves remain green long after being picked, rosemary became associated with the idea of remembrance. 采摘下的迷迭香树叶常绿不衰,因此人们把迷迭香树与怀念联系在一起 采摘下的迷迭香树叶常绿不衰 因此人们把迷迭香树与怀念联系在一起. 因此人们把迷迭香树与怀念联系在一起 31. although apparently rigid, bones exhibit a degree of elasticity that enables the skeleton to withstand considerable impact. 骨头看起来是脆硬的,但它也有一定的弹性 使得骨骼能够承受相当的打击 骨头看起来是脆硬的 但它也有一定的弹性,使得骨骼能够承受相当的打击 但它也有一定的弹性 使得骨骼能够承受相当的打击. 32. that xenon could not form chemical compounds was once believed by scientists. 科学家曾相信：氙气是不能形成化合物的. 科学家曾相信：氙气是不能形成化合物的 33. researchsintosthe dynamics of