Do you have anything to declare.

customs officers: 입국 심사관. 

Here you are = Here it is = Here you go.

declaration of independence = 독립선언문.

Anything prohibited or anything affected by tax laws 

= 금지품목이나 세법에 영향 받는 어떤 것 있나요?

That's what it means! => 그게 그 말이구나!

You can proceed. => 통과 하셔도 좋습니다. 

the customs office. / Alien ships = 외계인 우주선. 

I misunderstood it and said something stupid.

touch down =상륙하다의 의미도 있다.

I almost had a small problem. (조그만 문제가 생길 뻔 했다.)

He/She is a full package. (그 사람은 모든 것을 다 갖췄다.)

a piece of mail / furniture  !! ,but e-mail is countable. 

lower-cased letters / capital letters .