下面哪种固定液中含有过碘酸钠?()
A.4%多聚甲醛一磷酸二钠/氢氧化钠液
B.Zenker液
C.PLP液和PLPD液
D.PFG液
E.Müller液
参考答案:C
—Have you moved into your new classroom building?
—Not yet, it ______________.
A.was painted
B.is painted
C.has been painted
D.is being painted
三一专用生物肥生物固氮效应是怎么回事?