一些人对这种药物有不良反应。

A number of people have had a bad ___reaction to this drug.

有些人对海鲜有过敏反应。

Some people have an allergic ___reaction to seafood.

两个女孩对坚果有过敏反应，所以我们的午餐必须不含坚果。

Two girls have an allergic ___reaction to nuts, so our lunch must be nut-free.