There are three times __________.
It was just a __________ comment; I didn’t mean it to be taken so seriously.
Cycling is highly __________ to people’s health and the environment.
I’ve listened to Professor Smith’s talk about medicine,but I still haven’t got a good understanding of its key _________.
It was becoming increasingly _________ that he could no longer look after himself.
—She’s a lot older than you,isn’t she?—Fifteen years,to be _________.