孔子的中心思想是 [ ]
A.“仁”
B.“因材施教”
C.“温故而知新”
D.“兼爱”
答案:A
-You are very aren't you?
-Yes. Our team has won the game. [ ]
A. womed
B. sad
C. excited
D. frustrated
利用电磁铁来操纵阀心动作,实现油液流动方向变换的换向阀称为()。
A、液动换向阀
B、电磁换向阀
C、电液动换向阀
D、机动换向阀