三个张紧杆一方面是联接(),另一方面是传递()
参考答案:液压缸;研磨压力
I would appreciate _____if you could help me get a ticket in the Peak Transport in the Spring Festival Season.
A.you
B.that
C.this
D.it
维生素D缺乏性佝偻病的预防工作下列哪种是错误的()
A.孕妇多做户外活动
B.孕期后3个月适当补充维生素D及钙剂
C.新生儿出生后即口服维生素D
D.婴儿期尽早进行户外活动
E.母乳喂养及时添加辅食