Forgive me if I'm wrong, but haven't we met before.
如果我弄错的话请原谅我,我们以前见过面吧?
I suppose it's difficult for you to do this.
我推测对你来说做这件事情是很困难的。
It took him some time to connect the long rubber pipe to the air supply pipe that ran round the port, but at last it was done and as a result work was able to progress much faster.