Query Two Tables

hi,
I have two tables, 
 
 t1                    t2

col1                 col1    col2

 1                      1          0
 2                      1          0
 3                      1          1
 4                      2          0
 5                      2          0
 6                      3          1
 7                      3          1
 8                      4          1
 9                      4          1
 10                    4          1
 11                    4          1

t2.col1 is the key from t1.col1

I want to retrieve all t1.col1 records which equal to t2.col1 and tb2.col2 has ONLY "1"
the result should be: 3, 4

I try:

select tb1.col1 from t1 as tb1 where tb1.col1 in (select col1 from t2 where col1=tb1.col1 and col2=1 and ...???.)

any help?