1.His car runs fast but a race car runs faster. (AS....AS)
=> His car does not run as fast as a race car.
2.The girl worked hard. Her mother wasn't happy. (ALTHOUGH)
=> Her mother wasn't happy , although the girl worked hard.
1 => HIS CAR RUNS NOT AS FAST AS A RACE CAR DOES.
2 =>ALTHOUGH THE GIRL WORKED HARD, HER MOTHER WASN'T HAPPY .