1. 逻辑（上）的；（论证或推理方法）符合逻辑的
    In a logical argument or method of reasoning, each step must be true if the step before it is true.

    e.g. Only when each logical step has been checked by other mathematicians will the proof be accepted.
           只有每一逻辑步骤都被其他数学家验证之后，证明才能成立。

2. （结论或结果）逻辑上必然的，顺理成章的
    The logical conclusion or result of a series of facts or events is the only one which can come from it, according to the rules of logic.

    e.g. If the climate gets drier, then the logical conclusion is that even more drought will occur...
           如果气候变得更干燥，必然会出现更多旱情。
    e.g. ...this is the logical result of a long evolution in which we moved from working by the sweat of our brow and by muscle to industrial work and finally to knowledge work.
           这是长期进化的必然结果；在这一过程中，我们首先从事汗流浃背的体力劳动，然后是工业劳动，最后发展到脑力劳动。

3. 合理的；在理的
    Something that is logical seems reasonable or sensible in the circumstances.

    e.g. Connie suddenly struck her as a logical candidate...
           她突然想到康妮是个合适人选。
    e.g. There was a logical explanation...
           存在一个合理的解释。