The normal vector is just sticking straight up or straight down.

从而法向量的方向是竖直向上或向下的。

youdao

The problems are set up so that, if you start down the right path, it should be pretty straight-forward to work it through If you start down a plausible but incorrect path, you can sometimes find yourself stuck in the weeds somewhere, and we want to bring you back in.

问题提出了，如果你从，一开始就走正确的道路，解决的途径,就一目了然了,如果你走上一条貌似正确但实际错误的道路，你会在某时某刻,发现自己陷入泥沼，于是我们就会把你拉回来。

麻省理工公开课 - 计算机科学及编程导论课程节选

The two senators want to see the establishment of a bipartisan commission that would draw up a programme of budget reform to be submitted to Congress for a straight up or down vote, with no possibility of amendment, since amendments would surely cause the whole thing to unravel.

ECONOMIST: America's stimulus plan

In case you failed punk rock 101, pogoing is a dance where you jump straight up and down.

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Reportedly, House Speaker John Boehner (R-OH) has offered the option to his colleagues of voting on an amended version of the bill or a straight up or down.

FORBES: Move up http://i.forbesimg.com t Move down