牛倒地不起综合征通常不出现()
A、低钙血症
B、低钾血症
C、低钠血症
D、低镁血症
E、低磷酸盐血症
参考答案:C
The radio club often plays songs _______by students and gives messages to keep parents ____ of the latest news.
A.sung, exchanged
B.sang, broadcasted
C.singing, approved
D.sung, informed
He was about to tell me the secret_____ someone patted him on the shoulder.
A.as
B.until
C.while
D.when