54=6×9=36;
12a2b2=23ab.
故答案为:36,23ab.
2012 Olympic Games _______ in London. [ ]
A. will hold
B. will be hold
C. will held
D. will be held
中枢性呕吐的特点()
A.呕吐呈喷射状
B.呕吐后不感轻松
C.伴剧烈头痛
D.常呈顽固性
E.无恶心先兆