1. He made strenuous efforts to improve his reading.
    他奋发努力提高阅读能力。

2. It takes many years of strenuous training to be an outstanding athlete.
    要成为一名杰出的运动员需要多年艰苦的训练。

3. She is a strenuous supporter of women''s rights.
    她是妇女权利的积极支持者。

4. Is swimming a strenuous exercise?
    游泳是很费力的运动吗？

1. 吃力：5. ver [耗费] withstand | 吃力 : strenuous | 吃不消 : unable to withstand

2. 费力的：strengthening加强 | strenuous费力的 | Streptognathodus卷颚牙形石属

3. 奋发的：strenuosity 费力 | strenuous 奋发的 | strenuously 奋发地

4. 吃力的,奋发的,奋斗的：stationary 固定的 | strenuous 吃力的,奋发的,奋斗的 | subordinate 次要的,从属的

1. 费力的;繁重的;艰苦的
    A strenuous activity or action involves a lot of energy or effort.

    e.g. Avoid strenuous exercise in the evening...
           晚上不要做剧烈运动。
    e.g. These trips were strenuous, and the couple did not enjoy them...
           一路舟车劳顿，这对夫妇玩得并不开心。