that指代问题1.H was the author of more than 100 books for boys in the second half of nineteenth century {that} focused on the theme of success coming to those who work hard to achieve it.2.What they share in common,however,is the extraordinary variety of plant and animal life-forms {that} are a necessary part of the ongoing process of their fomation.

that指代问题
1.H was the author of more than 100 books for boys in the second half of nineteenth century {that} focused on the theme of success coming to those who work hard to achieve it.
2.What they share in common,however,is the extraordinary variety of plant and animal life-forms {that} are a necessary part of the ongoing process of their fomation.