Simplify the following text for a Grade 5 native English-speaking person.
Original: The original 777-200 model first entered service in 1995 , followed by the extended-range 777-200ER in 1997 ; the stretched 777-300 , which is 33.3 f longer , began service in 1998 .
Simplified: The original 777-200 model first entered service in 1995 , and the stretched 777-300 , which is 33.3 ft ( 10.1 m ) longer , was introduced in 1998 .