题目

美国布法罗大学的研究人员发现，无需加热只要加水，直径约10纳米的球形硅粒子几乎在瞬间即可产生纯度高的氢气同时生成硅酸（无毒的副产品），未来可作为便携式设备能源供给的一个潜在来源。右图是硅元素的部分信息，下列说法错误的是：（    ） A.原子序数是14                         B.硅元素是金属元素 C.原子核外有14个电子             D.相对原子质量是28.09  Because he wrote his name so that it could be read easily, John Hancock has a place in the dictionary. John Hancock was a wealthy man who helped the patriots in the American Revolution. He was president of the Continental Congress. He was also governor of Massachusetts and one of the first men of sign the Declaration of Independence. Yet he is remembered best for his large signature. The story is told that when Hancock sat down to sign the Declaration of Independence, he said that he would write his signature large enough for John Bull to read without his glasses. Hancock’s signature on the Declaration is four the three-quarter inches long—an inch longer than his usual signature. Today John Hancock can be used to mean any person’s signature.1. The passage is mainly about______________.A. the American RevolutionB. John Hancock’s handwriting C. how an American expression began D. signing the Declaration of Independence2. Hancock is remembered best because he________. A. was governor of Massachusetts B. helped the patriots in the Revolution C. signed his name in large letters D. was president of the Continental Congress3. According to the dictionary, a John Hancock is a________. A. governor                          B. man who sign petitionsC. strong patriot                     D. person’s signature