{#blank#}1{#/blank#} adj. 严肃的，认真的。

{#blank#}2{#/blank#}对某人/某事当真

Peter is serious about Jenny. He wants to get married to her.

{#blank#}3{#/blank#}对某事当真

He's serious about selling his house.

Last night I made a card very carefully {#blank#}1{#/blank#} {#blank#}2{#/blank#} I can send my mother a special present on Mother's Day.

{#blank#}1{#/blank#} it {#blank#}2{#/blank#}?

Lucy was doing her homework {#blank#}1{#/blank#}.

Ron {#blank#}1{#/blank#} {#blank#}2{#/blank#} Beijing three days ago.