在静电场中,将一个电子由a点移到b点,电场力做功10eV,下面判断正确的是( )
A.电场强度方向一定是由b指向a
B.电子的电势能减少了10eV
C.电势差Uab=10V
D.
答案:B
根据下面对话中的情景,从方框中选出恰当的语句填入对话中的空白处,使对话恢复完整.其中有两项是多余的.
John: Would you like to go to New York with me over the vacation, Jim?
Jim: 小题1: But where will we stay?
John: At my uncle´s. I always stay with him and there´s a room for you, too.
Jim: OK. He won´t mind?
John: Of course not. 小题2:.
Jim: Will we drive to New York?
John: Yes, it takes about six hours.
Jim: 小题3:
John: It may be cloudy and rainy. 小题4:.
Jim: Well, when will we leave?
John: 小题5:
Jim: No problem. See you then.
预制混凝土梁(板)安装的技术要求中,下部构造条件不包括( )。
A.下部构造的形状
B.下部构造的尺寸
C.下部构造的施工状况
D.架设孔数