We laugh at jokes, but seldom __________ about how they work.
“Long time no see”is _______sort of imformal, but it is part of ______language Americans use daily.
In this factory, suggestions often have to wait for months before they are fully _____.
----__________?----It depends on what it is.
. ______ is quite natural; a beginner can't read the books written in English very quickly.
----You forgot your keys when you left home in the morning.----Good heavens, ___________.