X线管内高速电子的动能取决于 （）
A.管电流
B.两极间的管电压
C.靶物质的原子序数
D.阴极灯丝焦点大小
E.X线管灯丝加热电压
参考答案：B
选择适当的单词填空。
1. The _______ (direct, direction) of wind is always changing in my hometown.
2. It is _______ (simply, simple) a phone number.
3. It's midnight and everything is ______ (sleep, sleepy) and quiet.
4. He is a great _______ (poet, poem, poetry) in ancient China.
5. His _______ (interrupt, interruption) stopped our meeting.
6. The _______ (expect, unexpected) knock on the door surprised every one.
细菌性 * * 病诊断标准不包括（）。
A.匀质稀薄白带
B. * * pH＞4.5
C.氨臭味试验阳性
D.线索细胞阳性
E.挖空细胞阳性
