There are so many models on sale that I don't know which one to {#blank#}1{#/blank#} {#blank#}2{#/blank#}.

You have {#blank#}1{#/blank#} {#blank#}2{#/blank#} {#blank#}3{#/blank#}; I think you'd better lose weight.

Tourists are bound to find their favorite food here, {#blank#}1{#/blank#} {#blank#}2{#/blank#} {#blank#}3{#/blank#} their Nationalities are.

It is the first time that I {#blank#}1{#/blank#} communicating with him face to face.

Those who make great contributions to our nation {#blank#}1{#/blank#}.

→The child has been badly treated, {#blank#}1{#/blank#}. (定语从句)

→{#blank#}2{#/blank#} is that the child has been badly treated. (主语从句)