题干
一Your English is very good.
一__________.
A：Thank you
B：Have a good day
C：No, very bad
D：OK
答案(点此获取答案解析）
A
一Your English is very good.
一__________.
A：Thank you
B：Have a good day
C：No, very bad
D：OK
因突变与染色体变异的叙述，正确的是