如何严防密封油带入氢冷发电机内?
参考答案:
应从改善密封系统,提高检修质量,加强运行调整几个方面着手,严格防止密封油带水漏入机内,一旦发生,应立即查明原因并采取有效措施。
75%乙醇消毒作用的原理是()
A.破坏细菌的细胞壁结构
B.破坏细胞膜,改变其通透性
C.使酶失去活性
D.与菌体蛋白结合
E.使菌体蛋白质脱水凝固变性
Directions:This section consists of three groups of pairs listed in two columns, A and B. You are to match the one marked 1), 2), 3) ,4) or 5) in Column A with the one marked a, b, c, d or e in Column B. One point is given to each pair you match. 1) ______ Jean Piaget 2) ______ M. A. K. Halliday 3) ______ J. Schumann 4) ______ Joseph H. Greenberg 5) ______ B.F. Skinner a) field, tenor and mode concept b) neo-behaviourism c) cognitive psychology d) the hypothesis of linguistic universals e) the acculturation theory