THE YOUNG AND PRODIGIOUS T.S. SPIVET( short 38/50 )

Hello everybody.My name is T.S.Spivet, I am ten years old and I am actually in sixth grade.Is there anyone in this room, who doesn't already at least have a PhD?So, I probably won't be teaching you much tonight.Any one? But I like to tell you three things.First, thank you ... Thank you for not cancelling my award 'cause I was younger than you expected.Second, the wheel.As you can see they are powered by magnets.Yet as you know, they demagnetize within approximately four hundred years. On a human scale, it sounds like a lot.In geological time, it's not even a fraction of a second. So, we're actually far from having a perpetual motion.Any Questions?Yes, what is the third point?

重点

at least/not less than

It'll cost at least 500 dollars.

She must be at least 40.

expect sth

We are expecting a rise in food prices this month.

Don't expect sympathy from me!

be powered by

The aircraft is powered by a jet engine.

fraction of

Only a small fraction of a bank's total deposits will be withdrawn at any six time.

She hesitated for the merest fraction of a second.

scale of sth/the size or extent of sth, especially when compared with sth else

They entertain on a large scale (= they hold expensive parties with a lot of guests).

Here was corruption on a grand scale.