Henry's electromagnet was______. A.exactly like Sturgeon's B.an improvement over Sturgeon's C.more dangerous than Sturgeon's D.not as good as Sturgeon's
A.A.exactly B.an C.more D.not
【参考答案】
B 解析：本题是一道具体细节题。问亨利的电磁铁与斯特杰恩的电磁铁有什么区别。文章第二段指出，在美国，一位名叫约瑟......