实施软件配置管理包括4个最基本活动，其中不包括（）。
A.配置项标识
B.配置项优化
C.配置状态报告
D.配置审计
参考答案：B
补全对话，每空一词。
A: Hello, Jack! 1______ was your weekend?
B: It was great.
A: So, what did you 2______?
B: On Saturday morning I 3______ my homework. On Saturday afternoon I 4______ to the movies with
my parents. On Sunday morning I visited my aunt, and on Sunday afternoon I 5______ basketball with
my friends.
A: Sounds like you had fun.
B: How 6______ your weekend?
A: It wasn't very good.
B: 7______ did you do then?
A: On Saturday I 8______ my mother do the housework. And on Sunday I studied 9______ the Chinese test.
B: You 10______ a busy weekend.
A: Oh, yes.
如图所示，电子从A点以速度v0平行匀强电场等势面沿AO方向射入电场（图中的平行线为匀强电场的等势面），由B点飞出匀强电场时速度方向与AO方向的夹角为45°．已知电子质量为m，电荷量为e．
（1）说明电场线的方向．
（2）求AB两点间的电势差UAB．
