医学界通过用14C标记的C60发现一种羧酸衍生物,在特定条件下,它可以通过断裂DNA抑制艾滋病病毒的繁殖。下列有关叙述中,正确的是A.14C与12C的化学性质完全不同 B.14C与14N含有的中子数相同C.14C60和12C60是碳元素的同素异形体 D.14C与12C、13C互为同位素
It’s high time you had your hair cut ; it’s getting _______ .
My friend showed me round the town, ______ was very kind of him.
They use computers to keep the traffic _______ smoothly.
If you leave the club, you will not be_____back in .
What I need is_____ book that contains ______ABC of oil painting.