下列不能证明一元酸HA为弱酸的是（   ）

A．NaA溶液的pH＞7(室温下)

B．pH试纸显示0.1 mol/L HA溶液的pH为2～3(室温下)

C．0.1 mol/L的HCl和HA溶液，前者的导电能力明显更强

D．HA溶液能与CH₃COONa溶液反应生成CH₃COOH

Looking out of the window of my room, ___ a tall tree in the yard.

A．there was

B．there were

C．I saw

D．there stood