powerful词义如下：
1、有权力的；有势力的；有影响力的
A powerful person or organization is able to control or influence people and events.
2、强壮的；强健的
You say that someone's body is powerful when it is physically strong.
3、大功率的；强效的；高效能的
A powerful machine or substance is effective because it is very strong.
4、强烈的，浓的
A powerful smell is very strong.
5、响亮的，洪亮的
A powerful voice is loud and can be heard from a long way away.
例句：
1、The expansion of higher education should be a powerful force for change.
高等教育的发展对变革应该是一个强大的推动力。
2、Cities have a powerful magnetizing effect on young people.
城市对青年人有着强大的吸引力。
3、The media has a powerful influence on public opinion.
传媒对于舆论有很大的影响。
4、I wasn't sure if I could handle such a powerful car.
我没有把握是否能驾驶功率这样大的车。
5、Only the intervention of powerful friends obtained her release.
经过有影响力的朋友们斡旋她才得以释放。