下列含氮元素的化合物,氮元素化合价最高的是[ ]
A.NO
B.NO2
C.N2O5
D.N2O
答案:C
.Please make my excuse at tomorrow's meeting. I've got too much work _____.
A.to do to come
B.doing coming
C.to do coming
D.doing to come
水痘若不注意护理,抓破感染可引起脓胞疮。