Different sentences
what is the difference between these sentences?
1a)my son, who lives in Texas, is an engineer.
1b) my son who lives in Houston is an engineer.
2a) politicians who lie are to be despised.
2b)politicians, who tells lies, are to be despised.
3a) I had a cocktail, wich was very unusual.
3b)I had a cocktail that was very unusual.
4a) I've met the man I want to marry.
4b)I've the man that I want to marry.
5a)I don't know where to park the car.
5b)I don't know where I parked the car.my answers:
1a) I think "who lives in Texas" is a explanation, the person has only one son.
1b)this person has more than one son.
2a)there are politicians that lies and politicians that doesn't lie.
2b)All politicians lie.
3a)every cocktail it's unusual.
3b)a specific cocktail is unusual
4a)this person doesn't park the car but is planning to.
4b)In this case, this person already parked the car but doesn't know where.