He was unable to make such progress, ____.
______ he is doing an operation on a patient; please don’t disturb him.
There has to ______ a well-developed system that can give people a warning when a tsunami is ______ the way.
—I hear Johnson ______ in the middle school.—What? I can’t imagine him ______ as a teacher.
He has passed the examination _____ his hard work.
I don’t like the pattern of the trousers. _____, the colour doesn’t suit me.