Historical experience can as a most important source of information.
I must be getting fat —I can____do my trousers up.
If you are feeling so tired, perhaps a little sleep would____.
We'd better take umbrellas—I'm sure it____when we arrive in London; it's always wet there at this time of year.
—Hi, Betty, are you free at present? I have to ask you for a favor.—_____.With pleasure
Steps must be taken _________ this kind of disaster will never happen again.