题目

Steven Contursi is an American. He has a hobby of collecting coins. He became well­ known because he owned a very special coin. It is thought as the nation's oldest silver dollar. In 1794, America began producing silver dollars. On the front of the coin was a drawing of Lady Liberty with long, straight hair; on the back was a drawing of the famous American eagle. About 1,750 such silver dollars were produced that year. But now, only about 150 are known to exist in the world. Luckily, Steven collected one. Even 216 years later, it still looks very fine. So many coin collectors have great inter下列各物质中互为同分异构体的是  A．1H与2H         B．O2与O3        C．乙烷与甲烷       D．正丁烷与异丁烷