x3m-n=x3m÷xn=(xm)3÷xn=43÷8=64÷8=8,
故选:B.
You'd better not speak of it at the beginning of the story, ________ it may give away the surprising
ending.[ ]
A. otherwise
B. then
C. so
D. which
简述由北大编制的“婚恋诊断测评系统”。