第4题: [单项选择]According to the professor, which of the following causes the evolution of a gas cloud into a star A. The internal gravity of the cloud. B. The thermal pressure of the cloud. C. The interplay between the above two factors. D. The lifetime of the gas cloud. 参考答案:C 答案解析:[解析] 本题为细节题,考查考生对话语事实和细节的捕捉。题目问:根据教授的解释,什么是导致星云演化成恒星的原因 教授说:“The internal gravity of an interstellar