Tony was very unhappy for _______ to the party.
It is uncertain ________ side effect the medicine will bring about, although about two thousand patients have taken it.
A lot of language learning,________ has been discovered, is happening in the first year of life, so parents should talk much to their children during that period.
Between the two parts of the concert is an interval,________ the audience can buy ice-cream.
The printer is of good quality. If it ________ break down within the first year, we would repair it at our expense.
They use computers to keep the traffic _________ smoothly.