通读全文，根据短文理解，选择最佳答案填空。

    My father is forty years old. He works in a 1 . He is a waiter. He is very 2 every day. He goes to work very early and 3 home very late. Our home is a bit far(远的) from his workplace, so he usually 4  a bus to work. He has a lot of things 5 every day. There are many people in the restaurant every day, and there are more people 6 Saturdays and Sundays. People like to come to the restaurant 7  it has some specials for dumplings every day. The bowls have three 8 small, medium, and large. If you don't have enough money with you, you may 9  them next time. My father is 10 to everyone, so people like to talk with him.

经过北京境内的河流受地势影响，均由____流向东南，注入渤海。

如图所示的杠杆中，OA=1m，OB=0.4m，物体重力G=100N，杠杆自身重力忽略不计，则关于此杠杆，下列说法正确的是（　　）