难: catastrophe; calamity; disas ...管: pipe; tube难管理: unmanageable难管理的: unmanageable难管制的: ungovernable难管教的儿童: problem child问题儿童, 难管教的儿童: problem child难关重重: a bundle of difficulties; a lot of obstacles难关: difficulty; crisis; barrier; tight squeeze 渡过难关 tide over a difficulty [crisis]; 攻克技术难关 break down a technical barrier; resolve key technical problems难怪找不到人都开会去了: no wonder you can't find anybody here难怪有人说电子计算机正渐渐接管世界: no wonder people say that computers are taking over the world难灌筑混凝土: unworkable concrete难怪风这么大: all the windows are open that