be at pains to

• adj. 煞费苦心(下苦功)

be at pains to的用法和样例：

例句

用作形容词 (adj.)

1. He was taking great pains to solve the problem.
   他正煞费苦心解决这个问题。
2. She took great pains in educating her children.
   她煞费苦心教育她的子女。