The bestl title for this passage might be()

他们将理论运用到了实践中，所以不仅降低了生产成本，而且提高了产品质量。(4分)

It has been found that about two thirds of all elements in the earth are metals. However, not all metals may be used industry.Metals used in industry are called engineering metals. The mostwidely used engineering metal is iron. (4 分)

宋朝为世界文明作出了三大发明贡献。(3分)

(一)将下列句子译成中文(8分)Like the principle of animal life,it frequently restores health and vigor to the constitution,inspite not only of the disease, but of the absurd prescription of the doctor.(4分)

交通阻塞

自由贸易

必修课

关税壁垒

(二)将下列词语译成英文(5分)一次装运

primitive people