49. Henry’s goal was to design and equip vessels that would be capable of making long ocean voyages without having to hug the shore.

亨利王子的目標是要使設計和裝備的輪船能進行長途的航行，而不需要經常靠岸。

50. Coal was one of the first minerals to be mined on a big scale, to provide fuel for heating homes.

煤炭是人們最早大規模開采的礦物質之一，其目的是為供暖提供原料。

51. During this time the selling price, and so profits, will go up and down depending on world demand.

在此期間，煤炭的銷售價格及其利潤會隨著國際市場的需求變化而上下波動。

52. Many of us believe that a person’s mind becomes less active as he grows older.

我們很多人都認為，一個人智力會因衰老而變得遲鈍。

53. This means that it took them longer to accomplish mental tasks than it used to.

這意味著他們完成智力活動所需的時間比過去長。

54. For example, the older person perhaps had trouble hearing, or poor vision, or inattention, or was trying to learn the new thing at too fast a pace.

例如，老年人也許聽力差，眼神不好，注意力不集中，或者想盡快地學會做某一件事情

55. Not only was the shop a center of buying and selling, but also a social meeting place.

過去商店不僅僅是一個買賣東西的地方，而且是一個社交場合。

56. He will have to give advice and make decisions as problems arise, and he must know how to get his huge staff to work efficiently with their respective responsibilities.

他必須為手下員工出主意，問題出現之后要做決斷，他還必須清楚如何使自己龐大的員工隊伍各司其職，高效工作。

57. Numerous studies have now shown that the overwhelming majority of colds are “caught” by hand contact.

許多研究表明，絕大多數的感冒是由于手的接觸而感染的。