1. Extraordinary discovery of echo-location in bats to see a case in which the vioce plays a strictly utilitarian role.
    我们只要从蝙蝠的回声定位这一项非凡的发明中, 就能看到声音起的纯粹实用作用的例子.

2. Ram had a good role model.
    拉姆有良好的行为榜样。

3. Over the next two decades, IIT graduates — educated at the expense of Indian taxpayers — played a major role in founding California's Silicon Valley.
    在接下来的20年中，印度技术学院的毕业生们——那些用印度纳税人的钱培养出来的毕业生——却在加利福尼亚硅谷的创建过程中发挥了主要作用。