This game is so difficult that I can't play it. (A) This is...play it
This is such a difficult game that I can't play it.
When I was young I lived near London. (TO) When I....
When I was young I used to live near London.
She's too tall to be a ballerina. (SHORT) She's.....to be a ballerina
She's not short enough to be a ballerina.