A:全部
B:②③⑥
C:①②③⑥
D:②③④⑥
—Is first impression very important?
—Yes, it is, because you never get second chance to make first impression.
已知等比数列{an}的前三项依次为a-2,a+2,a+8,则an=( )
O2 ____ 洗洁精 ____ 液态CO2 ____ 焊锡 ____
A.去油污 B.助燃器 C.粘接金属 D.灭火
a.熔化 b.氧化 c.乳化 d.气化