①浓盐酸 ②浓硫酸 ③烧碱 ④食盐 ⑤生石灰 ⑥稀硫酸.
A:①⑥
B:②③⑤
C:③⑤
D:②③④
Reading her biography, I was lost in admiration for _______ Doris Lessing had achieved in literature.
下列各式中,正确的是( )
胡萝卜先生先后用他的长胡子帮助过____、____。
等式x1-x=x1-x成立的条件是( )