Pruning, thinning and weeding are

Q. Pruning, thinning and weeding are:
A. Basically artificial activities based on human research
B. Natural phenomenon
C. Learnt from USA
D. Learnt from animals
Answer: Natural phenomenon

A. Basically artificial activities based on human research
B. Natural phenomenon
C. Learnt from USA
D. Learnt from animals
Answer: Natural phenomenon