display data using sql query

Question

subject	sem	status	risk
a	1	0	high
a	1	1	low

b	1	1	low
c	1	0	high
c	1	1	low

this is our table , i want the output is 

subject sem status risk

a            1      0      high

b            1      1      LOW

c             1      0     LOW

 

what will be the output.

plz help me..