急性肾盂肾炎最不常见的感染途径是（）
A.上行性
B.血行性
C.淋巴管感染
D.直接感染
E.以上均不是
参考答案：D
— I can't find my cell phone in my bag.
— __ it at home. [ ]
A. Have you left
B. Did you leave
C. Had you left
D. Do you leave
多肽链中主链骨架的组成是（）
A.-NCCNNCCNNCCN-
B.-CONHCONHCONH
C.-CHNOCHNOCHNO-
D.-CNOHCNOHCNOH-
E.-CNHOCNHOCNHO-
