In replacing the word “if" in the sentence “If petroleum gets into the lungs, it can cause quite a bit of damage to the lungs [including] pneumonitis, or inflammation of the lungs." (lines 57-60), the linking element that would significantly change the meaning expressed in the original is
In the fragments “to look at what we know and what are the gaps in science," (lines 20-21) and “'They may be lawyers, accountants, your next-door neighbor', he pointed out." (lines 40-41), the expressions look at and pointed out mean, respectively,