下列溶液中,能跟稀盐酸反应产生白色沉淀的是( )
A.AgNO3溶液
B.H2SO4溶液
C.NaCl溶液
D.Ca(OH)2溶液
答案:A
The blind man thought___________necessary to pay back the help people gave him when it was sunny.
A.that
B.it
C.this
D.him
不是定居人口腔的常见链球菌为
A.变形链球菌B.血链球菌C.轻链球菌D.米勒链球菌E.鼠链球菌