已知数列{an}是等比数列,a2=2,a5=16,则a1a2+a2a3+…anan+1=( )。
Peter, together with his parents_________every Sunday.
A.went hiking
B.go hiking
C.goes hiking
D.hiking
阻塞性黄疸时不出现()
A.血液中未结合胆红素增加
B.粪便颜色变浅
C.血液中结合胆红素增加
D.尿中胆素原减少
E.尿中出现胆红素