31.The study demonstrates that the quality of reaction accelerator can influence the density of refined copper.
31.研究表明，反应催化剂的质量影响精炼铜的密度。
32.It’s estimated that the claw hook of the cargo crane can’t heave the heavy lumber up.
32.据估计，该货物起重机爪形钩吊不起那些沉重的木材。
33.It’s inevitable that horrible earthquakes will happen in the margin of shifting earth layers.
33.移动着的地层边缘将不可避免地发生重大的地震灾害。
34.Steel rods that could reinforce concrete structures are indispensable in constructing.
34.钢筋可以加固混凝土结构，在建造过程中必不可少。
35.A scholar predicted that such festival decoration would be a typical feature (trait) of next magnificent ceremony.
35.一位学者预测，这种节日的装饰是下次盛大庆典的典型特征。
36.The earth’s axis is an imaginative line between the north and south polar and the equator divides the north and south hemisphere.
36.地球的轴心是介于南北极之间的那条假想的线；赤道是南北半球的分界线。
37.Sulfur dioxide is a toxic gas.
37.二氧化硫是有毒气体。
38.It is absolute that the string of a piano vibrates when the keys are struck.
38.钢琴的琴键一弹琴弦就想，这是再自然不过的事情了。
39.Emergence of the Internet is a grand symbol that mankind has access to a network era.
39.因特网的出现时人类进入网络时代的重大标志。
40.The philosopher said that human behavior is mostly a product of learning, whereas the behavior of an animal depends mainly on instinct.
40.那位哲学家说人类的行为主要是认知的产物，而动物的行为时本能的使然。