1. I am a software engineer and I work flexible hours.2. A study shows that software firms with flexible working hours perform better because employees to choose to work longer on the days they are more effective.
flexible working hours彈性上班 = 員工可選擇何時上班 = flexible working hours第一個例句不需要 working，因為 I work flexible hours 清楚表明是彈性上班的意思。
The janitor neglected his duty on the day the robbers broke nto the school.