下面代码的输出结果是()li=["alex","eric","rain"]s="_".join(li)print(s)
A. "_alex_eric_rain"
B. "alex_eric_rain"
C. "alex_eric_rain_"
D. "_alex_eric_rain_"
下面代码的输出结果是()lst1=[m+n for m in "ab" for n in "cd"]print(lst1)
A. ["aa","bb","cc","dd"]
B. ["cc","dd","aa","bb"]
C. ["ac","ad","bc","bd"]
D. ["ca","cb","da","db"]