(2) More than 300 members participated in this summer camp. More than 300 middle school students participated in this summer camp.
Test analysis: (1) The reason is improper collocation, so "open" should be changed to "open". Open means: remove obstacles, dredge, not stubborn, not conservative, not rigidly adhere to rules. "Opening" means: 1. Opening; Setting 2. Settings. There is work between the concepts of "middle school students" and "Communist Youth League members", but there are more than 300 Communist Youth League members attending this summer camp. More than 300 middle school students participated in this summer camp.
Comments: Generally speaking, to distinguish a sick sentence, look at grammar, look at meaning and look at rhetoric. In order to distinguish sick sentences quickly and accurately, in addition to reading more often to enhance the sense of language, we should also master certain methods, such as reading with a sense of language, combing branches, logical analysis and so on.