Choose the word closest in meaning to the underlined word: His suggestion on how to deal with the problem was found invaluable.
The Cameroon Cup Final match is usually __ shown on television.
Whenever cooking gas is scarce in the market, some dealers ... it.
The girls were too __ mature to discuss marriage.
Which is opposite in meaning to the underlined word: His behaviour is extremely volatile: no one can tell what she will do next.