答案

The reading material has proposed three possible methods to prevent birds hitting into tall buildings, but the professor claims that none of the three methods is effective enough to hinder the problem. Firstly, from the perspective of glass with pure color, the professor states his doubt, because according to the lecture, it explains that the birds will judge the new kind of glass a mirror and hit into the glass as usual. Secondly, judging from the glass with multiple colors, the professor holds a different view, because referring to the lecture, birds will try to find gap between each color and try hard to squeeze into the gap. Thirdly, on the point of man-made navigator, the professor never fails to express his concern, because in terms of the lecture, although it is possible to lead the birds into the right direction, the navigator will not work that well in short distance and the birds will still hit into the buildings. (160 words)