绝缘油水分检测，油样在运输、保管过程中要注意样品的防尘、防震、避光和干燥等，油样保存应不超过（）天。
A.5
B.6
C.7
D.8
参考答案：C
唾液淀粉酶作用最适宜的pH是
A．2.0～3.5B．3.5～5.0C．6.7～7.0D．7.0E．7.5～8.5
With the rapid development of recent years, the people, ____village I once worked in，live a happy life now.
A．who
B．in whose
C．whose
D．in which
