题干
—_______ do you go bicycling, Paul?
—About three _______ a week.
A：How often, times
B：How often, time
C：How long, times
答案(点此获取答案解析）
A
。则该DNA分子连续复制两次共需游离的胸腺嘧啶脱氧核苷酸的数目是（ ）