英文翻译高手进..

埃及金字塔气势宏伟号称世界七大奇迹之一,修金字塔时需大量的方石，在运方石时遇到一个问题，若一块方石其重为P牛顿，设此方石与地面之间摩擦系数为μ，用外力F拉方石使之移动，问此力与水平方向的夹角θ为多少时，最省力, 你能做到吗?试一试.
The imposing Pyramids is one of the senven wonders of the world, which needs a large number of square stones when it builds. However, there is a problem that if one square stone is P newton and the friction coefficient is μ, what is the degree of the separation angle θ when an external force F pulls the stone so that it is the most laboursaving? Can you do it? Have a try.

甲、乙两个工厂，甲厂位于一直线河岸的岸边A处，乙厂与甲厂在河的同侧，乙厂位于离河岸40 km的B处，乙厂到河岸的垂足D与A相距50 km，两厂要在此岸边合建一个供水站C，从供水站到甲厂和乙厂的水管费用分别为每千米3a元和5a元，问供水站C建在岸边何处才能使水管费用最省？
There are two factories A and B. The factory A locates in a place A along a straight river. The factory B is of the same side of A while it locates in a place B of 40km away from the river. The foot of a perpendicular D of factory B is 50km away from A. Now, if the two factories want to build a tank station C together and the prices of water pipe to factory A and B are 3a/km and 5a/km, where should the tank station C be built which can save money most?

Imposing pyramids of Egypt known as one of the Seven Wonders of the world, repair the pyramid will require a lot of side stone, square stone in the transport encountered a problem, if a square stone of its weight P Newton, set up this side friction between the stone and the ground coefficient μ, with the external force F pulling side stones to make it move, asked the level of this force and θ is the angle between the direction of the number, the most effort, you can do that? give it a try.

A, B and two factories, Company A produce a straight line in the river shore A Department Yichang with Company A produce the same side of the river, Yichang is located 40 km away from the river's B Division, Yichang to the riverbanks and the pedal D A distance 50 km, the two factories had to be on this coast in building a water supply station C, from water supply to the Company A produce stand and Yichang cost of water pipes 3a yuan per kilometer, respectively, and 5a yuan, and asked the water supply station built on the shore C Where can the water pipes of least cost?