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

I was amazed to learn that Picasso {#blank#}1{#/blank#} {#blank#}2{#/blank#} {#blank#}3{#/blank#} of more than 20,000 pieces of art.

The nations and organizations in support, of Trump's decision to exit from the Iranian nuclear deal were {#blank#}1{#/blank#} {#blank#}2{#/blank#} {#blank#}3{#/blank#}.

→After getting the work done, we put up a board {#blank#}1{#/blank#}. (定语从句)

→I must {#blank#}1{#/blank#} any inconvenience it may have caused you. (apology)

→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.