A：CH3OH和CH3OCH3
B：C6H5OH和C6H5CH2OH
C：CH3Cl和C3H7Cl
D：C17H35COOH和C17H33COOH
1.34____≈1.35
已知等差数列an的公差为2,若a1,a3,a4成等比数列,则a2=（ ）
A. He is playing ping-pong.
B. They are climbing trees.
C. She is singing and dancing.
D. I'm doing my homework.
E. It's running on the grass.
下列关于我国河流的叙述，正确的是（ ）
