— May I remind you that a Mr. Smith is waiting outside, sir? — Oh, that’s right. I ______ about it.
I have two grammars, ______are of great use.
That is not the way ______I do it.
He is working hard, ______will make him pass the final exam.
The reason ______he didn't come was ______he was ill.
This machine, ______for many years, is still working perfectly.