例句與造句

1. They include circular concrete pipes, larger rectangular pipes and modern rectangular section pipes.
2. I need a formula for calculating the electric field ( volts per metre ) just outside a round pipe located coaxially inside a larger rectangular section pipe.
3. Let's say the radius of the inner round pipe is r metres, the inside dimensions of the square section pipe is m metres and n metres.
4. It's difficult to find section pipe in a sentence. 用section pipe造句挺難的