1. We watched a cookery demonstration at school.
    我们在学校观看了烹调示范。

2. They aroused great interest at the time, they had important theoretical consequences, and they provided a striking demonstration of the potentialities hidden in instruments and apparatus.
    这些观察当时引起人们极大的兴趣，具有重要的理论意义，并充分显示出了仪表和仪器的潜在力量。