发酵食品的制作离不开细菌和真菌,实质上是与菌体内的 [ ]
A.抗生素有关
B.多种酶有关
C.有机物有关
D.无机盐有关
答案:B
Although he has been studying abroad,his parents try to keep him ________ of what has happened at
home. [ ]
A. warned
B. said
C. reminded
D. informed
五跨绝缘锚段关节两悬挂间及两悬挂其他各带电部分间的有效绝缘距离须大于()允许偏差()。
A、150mm;±50mm
B、250mm;±50mm
C、450mm;+50mm
D、450mm;±50mm