-- It's so cold! Why are your windows still open? --- Oh, they _______.
These are all ________houses for the homeless.
— Were you worried about him last night? — Yes. It was ________.
Now that he has missed his ________, he’ll have to wait for the next round.
We’ve always known him ________ a warm but calm character.
The step you have taken is ________ much risk(冒险).