计算:6x3÷(-2x)=______.
6x3÷(-2x),
=-(6÷2)x3-1,
=-3x2.
— No smoking here, sir!
— Oh, sorry. _____
A.Thank you for your reminding.
B.It’s none of your business.
C.What a great idea!
D.Do you want one?
某生物体细胞含有42条染色体,在减数第一次分裂前期,细胞核内含有的染色单体、染色体和脱氧核苷酸链数依次是()
A.42、84、168
B.84、42、168
C.84、42、42
D.84、42、84