骨骼肌牵张反射产生下列哪种作用()
A.受牵拉的肌肉发生收缩
B.伸肌舒张,屈肌舒张
C.屈肌收缩
D.所有关节的肌肉也同时发生收缩
E.伸肌和屈肌都收缩
参考答案:E
The number of people invited to the party _____ sixty, but a number of them ______absent.
A.were; was
B.was; was
C.was; were
D.were; were
为了保证电子产品的质量,检验工作应贯穿于整个生产过程中,只有通过检验才能及时发现问题。检验的对象可以是()。
A.半成品、单件产品或成批产品
B.元器件或零部件、原材料、半成品、单件产品或成批产品等。
C.元器件或零部件、原材料