下图标出的是有关灯泡组成的物质，请根据下图回答下列问题。

(1)所标物质中属于金属材料的是________，属于非金属单质的是_________。（各写一种即可）

(2)物质的性质决定其用途。请你就图中标出的物质举一例说明：____________。

(3)比较锡和铜的金属活动性强弱可采用________的方法。

There has been much speculation about the origin of baseball. In 1907 a special commission decided that the modern game was invented by Abner Doubleday in 1839. One hundred years later the National Baseball Museum was opened to honor Doubleday. Historians, however, disagree about the origin of baseball. Some say that baseball comes from bat-and-ball games of ancient times. It is a matter of record that in the 1700s English boys played a game they called "baseball". Americans have played a kind of baseball since about 1800. At first tile American game had different rules and different names in various parts of the country — "town ball". "rounders", or "one old cat". Youngsters today still play some of these simplified forms of the game.
Baseball did not receive a standard set of rules until 1845, when Alexander Cartwright organized the Knicker-bocker Baseball Club of New York City. The rules Cartwright set up for his nine-player team were widely adopted by other clubs and formed the basis of modem baseball. The game was played on a "diamond" infield with the bases 90 feet apart. The first team to score 21 runs was declared the winner. By 1858 the National Association of Baseball Players was formed with 25 amateur teams. The Cincinnati Red Stockings began to pay players in 1869.

Which of the following is true about the origins of baseball

A. Historians agree that baseball was invented by Abner Doubleday.
B. Baseball, as played in the early 19th century, differed very little from today’s game.
C. As early as the 1700s, English boys played a game called "baseball".
D. The first standard set of baseball rules was established at the turn of the century