含锑水样易水解析出沉淀,所以测锑水样在取样后应即刻加硝酸酸化至PH<2.
参考答案:错
解析:含锑水易水解析出沉淀,所以测锑水样在取样后应即废加盐酸酸化至PH<1.
Find ways to praise your children often, _________ you'll find they will open their hearts to you.
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唇的血液供应主要来自
A.阿颌内动脉
B.颌外动脉
C.甲状腺上动脉
D.内眦动脉
E.舌动脉