下列化学肥料属于复合肥料的是 [ ]
A.尿素:CO( NH2)2
B.重过磷酸钙:Ca( H2PO4)2:
C.氯化钾:KCl
D.磷酸二氢铵:NH4H2PO4
答案:D
My job was to wash bottles, which would then be filled with wine, or ______the filled bottles in boxes. [ ]
A. to put
B. putting
C. having put
D. being put
确定牙髓炎的患牙简便而可靠的方法是()。
A.温度测验
B.电活力测验
C.酸、甜测验
D.探查
E.叩诊