题干
On National Day there are more than six ___ people in the park.
A：thousands
B：thousand
C：thousands of
D：thousand of
答案(点此获取答案解析）
B
完全燃烧需氧气的物质的量是该有机物的n倍，生成CO2和H2O的物质的量相等。该有机物中n、x、y的关系是：