我国水上无线电通信规则中规定,海上无线电话业务共分为()种.
A、1
B、2
C、3
D、5
参考答案:C
The new suspension bridge ____ by the end of thismonth. [ ]
A. has been completed
B. has completed
C. is completed
D. will be completed
家庭制作甜酒时,常需往煮好的糯米中加入酒曲(菌种),其主要菌种是 ( )
A.酵母菌
B.醋酸菌
C.乳酸菌
D.霉菌