grind first meaning in English

粗磨

2 will we be able to prime grenades without having to throw them on the ground first
我能不先将手雷扔到地上再捡起来丢吗？
Affect field of sight . if you ' re on a plateau , you can ' t be seen from below ! hence : always occupy high ground first
高度差影响视野。如果你在一个高地上，下面是看不见你的。所以：首先占领高地！
The foot problem with toes touching ground first on walking may be possible to be corrected by orthosis . but this needs a professional assessment to decide it
走路时脚尖先着地的问题，可以通过矫形器来矫正，但是需要经过专业评估后再决定是否需要。
There is no worry about having any after - effects from walking , yet it yields results as good as those of other exercises . the proper way to walk is to let the soles of the feet touch the ground first and to maintain a certain rhythm . if you want to increase your walking speed , increase the frequency and not the length of your steps
不必担心走路会带来什么后遗症，而其益处也同其它的运动一样有效果，走路时，脚跟先著地，保持一个节奏，如果你想加快速度，应加快步伐而不是加大步伐，如加大步伐，惟恐你的膝盖受伤。