I was reading Shirley Hazzard’s novel The Transit of Venus. Though I (51) her other books, I had always resisted this one. It (52) me as too pure somehow, too heroic, larger or finer than life and therefore unreal. But now I read it with an almost (53) pleasure. There were sentences that (54) of gratification to my eyes and (55) the hairs on the nape of my neck. I was in a Boston hospital, propped tip in bed with a feeding tube in my arm after (56) surgery for cancer. It was

(57) double room and my roommate, who (58) when he spoke because he had both a broken chin and a drug habit was spraying the air for the fourth or fifth time that day with (59) had a television set and a radio going (60) . The diagnosis of my case was ambiguous. When I asked the doctor the usual question-How much time have I got—he hesitated before answering. "I would say," he said, "that you have in the neighborhood of years.\

60().

A. at the same time

B. at same time

C. on the same time

D. at the time

有A、B、C、D四种元素，已知A是地壳中含量最多的元素，B元素的原子失去一个电子只剩下一个质子，C元素组成的一种单质是自然界中最硬的物质，D^2-的电子层结构与氩原子相同。请回答：

（1）C元素组成的最硬物质的名称为           ，D^2-的离子符号为         。

（2）点燃A单质和B单质的混合气体能发生爆炸，其化学反应方程式为           ，所以点燃前需先检验          的纯度。