In this set of materials,
.... better say;
In the reading passage, ... You may start all integrated writing tasks with this phrase... that would help you manage time. I'd suggest you to stick to one pattern during your practice tests, and follow the same at the exam. That would really help you manage time at the exam.
however, the professor challenges the idea in the reading passage.
However, the professor challenges this idea by citing examples.I think you've done the necessary thing in the intro. You have briefly tole what the reading passage is about and then how the listening part responds to it. That's what they expect in the intro.
Then you can move on body paras, and talk about each point in detail.
First, the reading passage describes the scientists are working in making the microclimate for the plants to sustain their life; however, the professor states the opposite opinion because it is not easy to reestablish the same living environment since the microclimate is not as dryer as it should be.
.... good
I think you have a good idea about its structure. Good Luck!