Phrasal Verb : clam up, clamp down on, close down, come across, come forward

[영어대통령]

clam up : refuse to speak 

ex) When the teacher arrived she clammed up.

clamp down on : act strictly to prevent something 

ex)The government has decided to clamp down on smoking in public places.

close down : stop operating (company, restaurant, cinema). 

ex)When the factory closed down, the employees lost their jobs.

come across 1) find by chance 2) appear, seem, make an impression

ex)

1) Julie came across some photographs of her grandparents in the attic.
2) The candidate came across as a dynamic person during the interview.

come forward : present oneself 

ex)The police have asked any witnesses to come forward.