假设论证：条件状语从句 (Conditionals)

用于论证“如果不这样做，会有什么后果”或“如果这样做，会有什么通过”。这是扩展主体段 (Explanation) 的利器。

1. 第一类条件句 (Real Possibility)

用于预测未来的结果。

• Structure: If + Present, will + Verb
• Example: If the government invests in public transport, traffic congestion will decrease.

2. 除非 (Unless)

比 If not 更强有力。

• Example: Unless strict laws are enacted, pollution levels will not drop. (= If strict laws are NOT enacted...)

3. 一旦 (Once)

表示时间条件的紧密衔接。

• Example: Once privacy is compromised, it is difficult to restore.

4. 只要 (Provided that / As long as)

表示“在...条件下”。

• Example: Tourism is beneficial, provided that it is managed sustainably.

5. 虚拟语气 (Hypothetical - 偶尔使用)

用于假设非真实的情况，反而能反衬现实的紧迫。

• Example: If everyone cycled to work instead of driving, our cities would be much cleaner.