除去KCl(aq)中混有的少量MgSO4,所用的一种试剂是
A.KOH(aq)
B.NaOH(aq)
C.BaCl2(aq)
D.Ba(OH)2(aq)
答案:D
I carried the bowl with both hands________, so that I wouldn’t break it.
A.carefully
B.happily
C.quickly
D.carelessly
一对唾液腺中。下颌下腺分泌量约占总量的()
A.45%
B.55%
C.65%
D.75%
E.85%