and these

• 形形色色

and these的用法和样例：

例句

1. A flea has smaller fleas to prey on them, and these have smaller still to bite them, and so proceed ad infinitum.
   一只跳蚤有更小的跳蚤咬它，而后者有更小的咬它们，如此以至无穷。
2. This data is correct and These data are correct are both acceptable.
   数据正确(英文句中用is或are均可).