They were shown animated videos centering around numbers — for instance, one video showed eight frogs on lily pads; four jumped away at once, then two came back one at a time.

有些实验是一些和数字有关的动画，比如，某个视频里，有八只青蛙停在荷叶上，其中四只一下子跳的不见踪影，但两只马上又跳了回来。

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That's why it's been so shrewd to sort of pitch musicals right at kids, because almost every animated film has a couple of big musical numbers in it.

NPR: Do Movie Audiences Have a Tin Ear?

With terrific set designs and the best musical numbers of any of the old Rankin-Bass animated specials, it really holds up well even to this day.

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