第2题: [单项选择]临塑荷载Pcr是指塑性区最大深度Zmax为下列中的哪一个对应的荷载: A. Zmax=0 B. Zmax=1/4 C. Zmax=b/4 D. Zmax=l/4 参考答案:A 答案解析:临塑荷载Pcr是指塑性区最大深度Zmax=0对应的荷载,界限荷载P1/4是指塑性区最大深度Zmax=b/4对应的荷载。
第28题: [单项选择]The main purpose of changing main engine to electronic controlled is not to() A. control fuel injection time more precisely B. control fuel injection rate more precisely C. meet the environmental requirements D. meet high engine speed requirements 参考答案:D