1. The piston travels down on the intake stroke, up on the compression stroke, down on the power stroke and up on the exhaust stroke. 进气行程，活塞下行；压缩行程，活塞上行；做功行程，活塞下行；排气行程，活塞上行。
2. Ischemic stroke include the surgeries, stroke, cerebral vascular spasm hemorrhagic stroke include encephalorrhagia, subarachnoid hemorrhage, and so on. 缺血性中风包括脑血栓、脑栓塞、脑血管痉挛；出血性中风包括脑出血、蛛网膜下腔出血等。
3. AUTO GROUND: Automatic ground balance - raise search coil off ground, press the AUTO GROUND button, lower the coil to the ground, and release the button for precision auto-balancing. 自动地面：地面自动平衡-提高搜索起飞地面线圈，按AUTO按钮地面，降低线圈到地面，并释放精密自动按钮平衡。
4. There are strict demands on ground brush of ground installation, and different ground brushes produced by using different ways of burying ground wires. 接地装置的接地电阻有严格的要求，不同埋设地线的方法会产生不同的接地电阻。
5. Additionally there are ground-to-air, ground-to-ground, air-to-ground and air-to-air missiles, etc. 另外，还有地对空导弹、地对地导弹、空对地导弹、空对空导弹等。
