足辊的主要作用是什么?
参考答案:
刚离开结晶器铜管的铸坯壳薄,强度低,容易鼓肚变形,所以小方坯结晶器下部都带有铸坯支持即足辊。
Which of the following statements is NOT true
A.Quacks are really sympathetic.
B."Snake oil" does not work.
C.Doctors cannot cure all ills.
D.Patients are often impatient.
药物首过效应是指()
A.药物通过粪便排泄
B.药物在肌肉受酶的作用发生变化
C.药物通过 * * 部分排泄
D.药物通过肠粘膜和肝脏时产生生物转化、减少循环有效药量
E.药物通过胃肠道受消化液的影响