WHAT IS THE MAIN TOPIC OF THE PASSAGE

1, - 9 DE HSG ANH 12 CHON LOC CO KEY
9 DE HSG ANH 12 CHON LOC CO KEY
1,What is the main topic of the passage ?a-The relationship between a plant’s roots and its shoots.b-What can be learned by growing roots in isolation.c-How plants can be grown without roots.d-What elements are necessary for the growth of plants.