—It's nice______on a fine day.

—It is good for your health.                      [ ]

A. to take a walk              

B. to taking a walk            

C. taking walk

据报道，科研人员利用电子计算机模拟出类似C₆₀的物质N₆₀。试推测该物质不可能具有的性质是

A．N₆₀不易溶于水

B．稳定性弱于N₂

C．熔点低于N₂

D．相同物质的量时，N₆₀的质量大于N₂