最常见的是first…second…third。还是需要保持一致性，保证观赏性和可读性。

示例：

A: Jiang said that the Party should now concentrate on the following three aspects:

First, the whole Party must keep its ideological and political unity.

Second, the unity of the Party in organization and action to be enhanced through implementation democratic centralism.

Third, Strength further the close relationship between the Party and the people, putting the struggle against corruption at the top of the agenda. (first后面接整个句子，second后面接名词短语，third后面接祈使句)

B: Jiang said that the Party should now concentrate on the following three tasks:

First, it must maintain its ideological and political unity.

Second, it must enhance its unity in organization and action by implementing democratic centralism.

Third, it must strength its close relations with the people, placing the struggle against corruption at the top of its agenda.(使用it must do sth句型保证统一性)

一系列同一级别的标题，最好也是保持一致，设定一个统一规则。

示例：

Seizing the Opportunity to Speed up Economic Development