data of 1 stu is in 3 rows i want in 1 row in sql

Question

from this

STU	SUB
1	MAT
1	CHEM
1	PHY

 to this

STU	SUB1	SUB2	SUB3
1	MAT	CHEM	PHY

data of 1 student is in 3 rows i want in 1 row in sql