It is often ____ that human beings are naturally equipped to speak.
An idea ___ into my mind that we should go there by bus instead of on foot.
---You’ve made great progress in your studies of English, haven't you?---Yes, but much___.
The hall __ we saw the film was very clean.
--Let us see your pass, ___. ---Sure.
I can't __ the difference between them because they look like the same.