I'd love to sail           the Pacific．

A．through            B．across              C．over                   D．above

Paul and Jason were brothers who lived and worked on neighbouring farms．For 35 years they farmed side by side，sharing machinery and goods as needed，without a single problem．
However，one autumn，things changed．It began with a tiny disagreement about a horse，which grew into a major difference．The difference led to angry words，followed by weeks of silence between the two brothers．
One morning there was a knock on Paul’s door．He opened it and saw a builder holding his toolbox．“I’m looking for a few days’work，”the builder said．“Are there any jobs here I could help with?”
“Yes，”answered Paul，extremely pleased to see the builder．“I do have a job for you．Look at that farm across the creek(小溪)．That’s my brother’s farm.That creek used to be a grass field，but last week my brother dug a path from the fiver and made the creek．But I’ll go him one better．See that pile of wood?1 want you to build me a fence，two metres tall，so 1 won’t need to see him anymore．”
The builder said thoughtfully．“I think I understand the situation and I'll be able to do a job that pleases you．”
Paul had business in town that day and left the builder to his work．When he returned，the builder had just finished his job．Paul was shocked．Instead of a fence there was a bridge，stretching from one side of the creek to the other．
As Paul stood on the bridge，staring in amazement，his younger brother Jason，came across，and took Paul’s hand．“You are a good man to have built this bridge after a11 I've done，”said Jason．
Then，Paul，with tears in his eyes，said to the builder who was packing his bag to go，“Thank you so much。Please stay．I have much more for you to do．”
“I’d love to．”the builder said quietly，“but，I have many more bridges to build.”
【小题1】What was the cause of the disagreement between the two brothers?