叠层生产的预应力构件放松预应力筋时,应从下到上顺序进行。
参考答案:错
I _____while my friend _____ TV.[ ]
A. arrived; was watching
B. was arriving; watched
C. arrived; watched
D. was arriving; was watching
急性CO中毒的主要机制是()
A.与含二价铁的肌球蛋白结合,损害线粒体功能
B.与红细胞的Hb结合,形成HbCO,引起组织缺氧
C.抑制细胞色素氧化酶的活性
D.产生高铁血红蛋白
E.影响呼吸链的电子传递