【单选题】1243年,蒙古人拔都以( )为都城(今伏尔加格勒附近)建立钦察汗国,又名金帐汗国
【简答题】I was told that there were about 50 foreign students _____ Chinese in the school, most _____ were from Germany. A.study of whom B.study of them C.studying of them D.studying of whom
【单选题】在输出制动力矩相同的情况下,尺寸和质量一般较小的制动器()
【判断题】对比鼓式制动器,在输出相同制动力矩的情况下,盘式制动器尺寸和质量一般较小。A. 对 B. 错
【判断题】在输出制动力矩相同的情况下,盘式制动器的尺寸和质量小于鼓式制动器。
【单选题】水的质量密度为1.00,电子密度为3.34,有效原子序数为7.42,最适合替代的组织是