已知某气体的状态方程为 p = RT/(v-b) – a/v2，其中a和b为常数。气体经历等温过程从状态1变到状态2，该过程中的熵变(s2-s1)T =______。
A、A
B、B
C、C
D、D

单项选择题Peter und Flora, _____ ihr Kollegen? A、seid B、sind C、bist D、ist

单项选择题What can be learned from Little Miss Sunshine and Forrest Gump? A、It is important to be competent. B、It is important to be optimistic. C、It is important to be confident. D、It is important to be friendly.