移植心脏病人的血钾应不超过()
A.3.0mmol/L
B.3.5mmol/L
C.4.0mmol/L
D.5.0mmol/L
E.6.0mmol/L
参考答案:B
精馏塔塔顶回流的作用是什么?
There is too much noise outside; I can't____ my attention on my book. [ ]
A. consult
B. connect
C. pay
D. concentrate