Which of the following statements are correct?
1. Knots in a tree affect the continuity of fibres.
2. Nail knots do not influence the strength of timber.
3. Druxiness of wood is not a defect.
4. Tall trees with twisted fibres give good timber for poles.
1
1, 2, 3 and 4
2
1, 2 and 4 only
3
1, 2 and 3 only
4
2, 3 and 4 only