The use of multimedia courseware on the "the edge of a knife" in teaching can achieve the goal and effect that cannot be gained by the traditional education.

在教学中把多媒体课件用到教学的“刀刃”上，能达到传统教育不能达到的目的和效果。

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The game is poised on a knife-edge. One mistake or one piece of good luck could decide it.

比赛形势扑朔迷离。一个失误或是一点运气就有可能决定胜负。

《柯林斯英汉双解大词典》

Half a mile away there's another thumping great bronze, the two-section 1962 Knife Edge, opposite the House of Lords - a site chosen by Moore for its high visibility.

半英里之外还有另外一件庞大的青铜雕塑，1962年的两片《刀锋》，位于英国上议院对面——因为位置醒目摩尔选择了这里。

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The other a jagged line, like the edge of a steak knife.

BBC: How to buy jade in Asia

Using beams of electrons, he carved a cantilever out of the edge of each crystal (think of a knife held down on a table, with the blade sticking out).

ECONOMIST: Small-scale physics

Run a long, sharp knife around the edge of the cake and invert it onto a small rack, then invert it again onto a second rack so that the cake is right side up to complete cooling, 30 minutes more.

CNN: Food Central - Recipes - Incredible Melted Ice-Cream Cake