用现代汉语翻译下面句子
这棵树树干的横截面的直径大约是多少米？
根据短文理解，选择正确答案。
For Rent
A big apartment for a family of four people. ￥ 2,000 a month. Call Mr. Zhang.
Tel: (010) 8433-9211
Room Wanted
Look for a single（单人的）room under ￥ 650 a month. Please call Carrie at (010) 8433-9236.
Lost
ID card Name:Tracy Number: 232324198804125510
Please call (010) 8838-7166.
For Sale
Come and buy school things!
All kinds of school things!
Soccer ball:￥50 Basketball:￥40 Pen:￥15
Only five days, this week!
Lantian School Things Store, between No. 1 High School and Renmin Hospital
Shop keeper: Mr. White Tel: (010) 8836-7166
尧舜时期，采用筑堤堵水和疏通河道相结合的方法，把汹涌的洪水引入大海的治水英雄是( )
