处于平衡;状态的杠杆,受到微小扰动后,能在任意位置继续保持平衡,这是()。
A.稳定平衡
B.不稳定平衡
C.随遇平衡
参考答案:C
—Remember the first time we met?
—Sure.You__________ the novel Pride and Prejudice in the library.
A.had borrowed
B.have borrowed
C.were borrowing
D.borrowed
了解特种铸造的基本特点对采用和发展特种铸造方法有什么实际意义?