他的工人全是老黑和老墨。

底面板有一颗螺丝不见了，分明是还有打开主机箱的可能 （我的是laptop）。If you try to open a cover with so many screws, be very careful, otherwise, there will always one or two screws missing. You see, now there is one screw missing. hehe:-(

The owner said:

1. you might already changed HD yourself before coming to my shop.

2. that screw was loose by itself after a long time of using and dropped somewhere before coming to my shop.

hehe, I agreed with him, because we will see each other every week. If is my fault, because I should not have created this evil change to fail people and induced some low life to make mistake. Be careful next time.

I am going to buy a screw.