发布时间：2013-05-04 16:18:25

The fourth way to set the pump suction tank before, as shown in figure 5. In this way the need to pump water pipe is provided with a water tank, water pump in the first run, the tank should artificial filled with water, the first time after stopping operation, because the water tank is higher than the height of the water pipe in pipe the water height, ......【阅读全文】

发布时间：2013-05-04 16:14:41

IELTS雅思写作往往是考试中考生最头痛的部分，因为很多时候都发现自己有过多的东西要说，有过多的内容要放进去，或者因此而彻底忽视了时间的掌控，导致超时，草草交卷了事。其实写作中最重要的就是要处理好内容和时间的辩证关系，否则考生纵有满腹诗书也难以发挥。......【阅读全文】