关键是that的用法.结果满意的话,追加50分.

你引的句子是：He is the only one that trusts me. 其中，is 是跟主语He，trusts 跟从句的主语 that，关系代词 that 指代one。 它与这句不同： ...and only those 【who are able to take advantage of the opportunities for success and happiniess】 that can succeed. 显然，can succeed 跟主语 those，因此that是多余的。 书后练习仿照了课文的句子： Nothing lay ahead of us but exertion, struggle, and perseverance. Those who were able took advantage of the opportunities for success and happiness that presented themselves amid the worries. 【这是原版的，谷歌能找到。】 其中，that 指代的是opportunities, 即opportunities presented themselves。 注意：who were able 修饰those，谓语动词跟的主语是 those。

编书者粗心，竟把who were able took advantage of 看作 who were able to take advantage of 然后这个句子就套到了练习中： those who are able to take advantage of 实际上，原句的结构是： Those 【who were able】 took advantage of 【the opportunities for success and happiness that presented themselves 】amid the worries. 意思：当机遇伴随忧虑出现的时候，那些有能力者抓住了机遇，（走向）成功和幸福。 所以，这个句子：and only those who are able to take advantage of the opportunities for success and happiniess that can succeed. 需要改为：and only those who are able take advantage of the opportunities for success and happiniess.

不客气！