尿沉渣细胞检查时，至少观察高倍视野（）.
A.5个
B.10个
C.15个
D.20个
E.25个
参考答案：B
填入所缺单词完成句子。
Many years ago people didn't travel by ______________. They didn't travel by ______________.
They didn't travel by ______________.
A．甲车开始开动
B．甲乙两车开始向相反的方向开动
C．乙车开始开动
D．上述情况都有可能
