单项选择题使用60.0MHz的仪器,TMS吸收和化合物中某质子之间的频率差为180MHz。若使用40.0MHz的仪器,则它们之间的频率差是 A、120 MHz B、100 MHz C、160 MHz D、180 MHz
未分类题A manufacture packages soap powder in containers of three different sizes. The amount of soap powder in a full large container could fill exactly 3 of the medium containers or exactly 5 of the small containers. If an equal number of small and large containers are to be filled with the amount of soap powder that would fill 90 medium containers, how many small containers will be filled?E.55
多项选择题Thinking is a kind of cognitive activity, a rational stage of cognition, with abstraction, () and other characteristics.
单项选择题变压器运行时,其绕组和铁芯产生的损耗转变成( ), —部分被变压器各部件吸收使之温度升高,另一部分则散发到周围介质中。 A. 热量 B. 有功 C. 无功 D. 动能
未分类题A school bus has 10 double seats in each of 2 rows. Two students can sit in each double seat. If an empty bus starts out and makes two stops, picking up three times the number of students at the second stop as at the first stop, and if the bus is then filled to seating capacity, how many students got on the bus at the second stop?E.30