Three subjects must be taken, viz., English, mathematice and history.

三个科目是必修的, 英文, 数学和历史。

On most farms you'll find only 5 kinds of animal, viz. horses, sheep, cattle, dogs, and pigs.

在许多农场只能看到五种动物，马、羊、牛、狗和猪。

Three vacations occur in the course of the year,viz,two weeks at Christmas,ten days at Easter and the usual two months in summer.

一年中有三个,圣诞周,复活以及通常的个月暑。

Evolving process of hub dynamo which used in bicycle is presented. The performance of magnetite viz. ferrimagnetism or NdFeB is analyzed. The prospect of marketing is viewed.

摘要介绍了自行车上使用的花鼓式发电机的演变过程，分析了所用磁石，铁氧体或钕铁硼的性能优劣，并进行了市场前景展望。