翻译下列短语

1．看起来像                               

2．喜欢做某事                               

3．过去经常做某事                               

4．关怀,照顾                               

5．适合于……的                              

DNA变性时，断开的键是

A．磷酸二酯键
B．疏水键
C．糖苷键
D．肽键
E．氢键