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 in isolation D. What elements are necessary for the growth of plantsE. None of the avobe   2. The word themselves in line 1 refers to - A.  A plant physiologists                B. Solution  C. RootsD. Laboratory flasksE. None 3.  According to the passage , What is ATP? A. A biochemical processB. The tip of rootC. A type of plant cellD. A type of plant cellE A chemical compound        4. The phrase'got along fine ' in line 4 means - A. Grew wellB. Become slenderC. Lokked niceD. Grew longerE. None