①If I have a toothache,{#blank#}1{#/blank#}               A.I should take some medicine.

②If I have a problem,{#blank#}2{#/blank#}          B.I visit the dentist.

③If I see an accident,{#blank#}3{#/blank#}                C.I should call the police.

④If I don't know something, {#blank#}4{#/blank#} D.I should ask the teacher.

A:What's the matter?

B:I have {#blank#}1{#/blank#}  {#blank#}2{#/blank#}.

A:I'm sorry to hear that.{#blank#}3{#/blank#}  {#blank#}4{#/blank#}.

B:Thank you.