Defects such as blisters and cracks in bitumen may be caused by natural agencies such as
1. Water
2. Air
3. Light
Of the above, the correct agency (ies) is/are
1
1 alone
2
1 and 2
3
1 and 3
4
1,2 and 3
Defects such as blisters and cracks in bitumen may be caused by natural agencies such as
1. Water
2. Air
3. Light
Of the above, the correct agency (ies) is/are