begood to後面加什麼?

　　雙語例句

　　1.You have to be good at spotting trouble on the way and heading it off.

　　你必須善於發現潛在的麻煩並加以化解。

　　2.A teacher should be good at drawing inferences about other cases from one instance.

　　老師要善於舉一反三。

　　3.Viruses tend to be good at surviving when a computer system crashes.

　　計算機病毒在系統崩潰後往往依然存在。