Passage B
Related Information

Pro Circuit
In some professional sports such as tennis, golf, bowling, and track, professional athletes travel from town to town and sometimes from country competing in weekly events. This is called the Pro Circuit or Pro Tour. The major events, such as the U.S., British, French, and Australian Opens in tennis are part of the Pro Circuit.

职业巡回赛:
某些职业竞赛，如网球、高尔夫球、保龄球和田径赛的职业运动员，从一个城市到另一个城市，或从一个国家到另一个国家进行比赛。这种竞赛就称为职业巡回赛或巡环赛。主要的赛事有：美国、英国、法国和澳大利亚网球公开赛。

Leading Computer Companies
The two leading computer companies in the world are IBM (International Business Machines) and Microsoft. IBM specializes in hardware, and Microsoft specializes in software. Windows is clearly the dominant software format, and this may be Microsoft's greatest contribution to the computer industry. The PC (personal computer) was actually pioneered by other companies such as Apple, but IBM has met this challenge with PC's of its own and still dominates the field.

主要计算机公司:
全球两大计算机公司是IBM和微软。IBM以硬件见长，而微软则主攻软件。微软的Windows显然是软件业的主导，也是微软对计算机行业的巨大贡献，PC机的先驱无疑非苹果公司等莫属，但IBM勇于挑战，以自己的品牌在硬件业独占鳌头。