题干
Why doesn't Jill go shopping?
A：Because she wants to look at her sister．
B：Because she wants to look for her sister
C：Because she has to look after her sister．
答案(点此获取答案解析）
C
内切酶EcorⅠ，能识别DNA分子中的GAATTC序列，切点在G与A之间。这是应用了酶的 ( )
