For all the professional athletes, _______to the Olympics means that they have a chance to enter the history books.
A:approach
B:method
C:way
D:access
孙的笔画顺序是____。
某元素的一种同位素X的原子质量数为A,含N个中子,它与1 H原子组成HmX分子,在ag HmX中所含质子的物质的量是