—Learning a language isn't easy. It takes time.
    —I agree. ______. There's no shortcut.
 
【正确答案】 B
【答案解析】 All roads lead to Rome，“条条大路通罗马”；Rome wasn't built in a day，“罗马不是一天建成的(或冰冻三尺非一日之寒)”；Practice makes perfect，“熟能生巧”。根据句意应该选B。