You get TIRED from exertion, from difficult or long-sustained effort—running a marathon, doing errands all day, managing your home and your kids' lives.
Even a modest force, if sustained over a long time, would do.
如果它持续很长的时间的话,即使风力不大也可以做到。
3
Second, the likely path to a long, sustained, rapid boom is to have had sufficiently tragic events and perverse policies that forced a country far from its potential.