Match the idioms to the meanings: a Keep one's shirt on
b Caught with one's pants down
c Under one's hat
d Too big for one's boots
e Tighten one's belt
1 spend less money than before
2 to be discovered doing something
3 not to overreact, to be calm
4 to have too much self-confidence
5 to keep a secret, not mention it
a 3
b 2
c 5
d 4
e 1
a - 3, b -2, c - 5, d - 4, e - 1.