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

Pigeons {#blank#}1{#/blank#} {#blank#}2{#/blank#} {#blank#}3{#/blank#} a compass inside them which tells them which way is north.

The doctor {#blank#}1{#/blank#} my staying in bed to have a quick recovery.

{#blank#}1{#/blank#} {#blank#}2{#/blank#} {#blank#}3{#/blank#} not for his fluency in English, he couldn't have been offered the job.

→From my point of view, our library should buy some popular science books and literary books because they are very {#blank#}1{#/blank#} {#blank#}2{#/blank#} us.

{#blank#}1{#/blank#} is well known, the horse will run faster if {#blank#}2{#/blank#}.