单选题：Beef is an excellent material of iron.

题目内容：

Beef is an excellent material of iron. A．beginning
B．storage
C．source
D．substance

参考答案：

答案解析：

Knowing that I had been out of work now, they were unwillin

Knowing that I had been out of work now, they were unwilling to lend me money.A

分类：理工类题型：单选题

分类：理工类题型：单选题

Fermi was famous for inventing a device to calculate bomb's energy accurately.A

分类：理工类题型：单选题

Fermi, an experimentalist as well as a theoretician, won a Nobel Prize for prod

分类：理工类题型：单选题

有以下程序程序运行后的输出结果是A．8，17 B．7，16 C．8，8 D．7，17

分类：理工类题型：单选题