QT450-10的基体组织是()A.铁素体 B.铁素体+珠光体 C.珠光体+铁素体 发布时间:2017-10-04 23:54 │ 来源:www.tikuol.com 题型:单项选择题 问题: QT450-10的基体组织是()A.铁素体B.铁素体+珠光体C.珠光体+铁素体D.珠光体
题型:单项选择题 He ______ trees in his garden just now. [ ]A. was seen planting B. was seen plant C. is seen to plant D. has been seen to plant 查看答案
题型:单项选择题 平面四连杆机构ABCD如图所示,如杆AB以等角速度w=1rad/s绕A轴顺时针向转动,则CD杆角速度wCD的大小和方向为:()A.wCD=0.5rad/s,逆时针向B.wCD0.5rad/s,顺时针向C.wCD=0.25rad/s,逆时针向D.wCD=0.25rad/s,顺时针向 查看答案