Choose the mistakes．（找出下列每句中的错误).()1. Our school is biger than your school.
AB C
( )2. -Is Sam stronger than Lingling?
A B
-Yes，heisn't.
C
()3. Sam isshort than Daming.
A B C
()4.The Changjiang River is longer than the yellow River.
AB C1-4 B C B C