举高车操作者一定要牢记，只有当臂架起升到一定角度时才可以回转或伸臂。
参考答案：对
I feel greatly honored_____to make a speech in your school.[ ]
A. to invite
B. inviting
C. to be invited
D. invited
带有纯合裸基因（nu/nu）的小鼠有哪两个主要特征缺陷？
