How to delete only one line of a *.txt file????

e.g. "dictionary":

Boston - city in USA
California - state in USA
dog - an animal
cat - also an animal

and now I want to delete "California - state in USA"!!!

How can I do it?



and another question


how can I load only one line of a *.txt file:

e.g.

first load:

Boston - city in Usa

then:

second load

California ........

but withou deleting the line before....???



Thanx in advance

ALanAir23