meaning if seal

[Ermak]

English Language Tests, Intermediate level

ESL/EFL Test #273 "When do you say this?", question 9

I say "Your lips must be sealed" when I ..........

(a) tell someone to be quiet
(b) want someone to keep a secret
(c) want someone to stop eating

English Language Tests, Intermediate level

ESL/EFL Test #273 "When do you say this?", answer 9

I say "Your lips must be sealed" when I want someone to keep a secret.

Correct answer: (b) want someone to keep a secret
_________________________

what´s the sealed?

Ermak

[Conchita]

To seal is to close tightly.