根据一些常见的标志，我们可以判断是否存在指代，并应用其解题。

1. 限定词+名词：

the/ this/ that/ these/ those/ such/ both/ another/ other+n.

2. 指示代词：

this/ that/ it/ one/ ones

下面我们用几个例题来感受下：

(限定词+名词)：

【例1】 Another option: Climb high and look for signs of human habitation. For example, even in dense forest, you should be able to spot gaps in the tree line due to roads, train tracks, and other paths people carve through the woods. Head toward these 16 to find a way out. (2019英一)16. [A] posts [B] breaks [C] shades [D] links

首先，我们先判断四个选项。A post邮寄，岗位。B break打破，裂缝。C shade阴影，阴凉。D link联系。解决这道题目时，我们需要判断出these+空格处是指代。指代要往前还原，可以找出上句中gaps沟，缝，四个选项中和gaps较接近的是B选项，即为正确答案。

【例2】Curiosity is often considered a good instinct—it can lead to new scientific advances, for instance—but sometimes such 13 can backfire. (2018英二)

13. [A] inquiry [B] withdrawal [C] persistence [D] diligence

该题目解题的关键在于能够理解“such+空格处”指代的内容。根据句子内容，我们可以了解到前面的主语为curiosity(好奇)。从四个选项A探索，B撤退，C坚持，D勤奋。所以正确答案为A选项。

(指示代词)：

【例1】One of the remarkable findings of the study was that the similar genes seem to be evolving 15 than other genes. Studying this could help understand why human evolution picked pace in the last 30,000 years, with social environment being a major contributory factor. (2015英一)15. [A] faster [B] slower [C] later [D] earlier

该题目中，“相似的基因看起来进化的比其他基因进化的 ，”四个选项“快，慢，晚，早”搭配都合适，但是在后句中有this指代，“研究这一点有助于理解人类为什么在过去三万年中的进化加快了”。所以A项正确答案。

【例2】As for me, weighing myself every day caused me to shift my focus from being generally healthy and physically active to focusing 3 on the scale. That was bad to my overall fitness goals. (2019英二)

3. [A] initially [B] occasionally [C] formally [D] solely

解决该题目，先解决选项问题：A较初地，开始地，B 偶尔地，C正式地，形式上地，D仅仅。从搭配来看“focusing 3 on the scale(称)”A“开始，较初”关注称。B“偶尔”关注称。C“正式地”关注称。D“仅仅，只”关注称。四个选项的搭配都是合理的。但是，下句中出现了that指代“那对我的整体健身目标来说是非常糟糕的”。我们可以判断出，“只关注称上的数字时”会对我们的健身目标不利。所以正确答案为D。