题干
When asked about his childhood, the man was found . Obviously, it is a scar he doesn't want to be touched.
A：choked up
B：sprung up
C：split up
D：broken up
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（ ）