给下面的句子选择合适的答语。①Happy birthday! {#blank#}1{#/blank#} A. Two books.
②How old are you? {#blank#}2{#/blank#} B. Thank you.
③How many books? {#blank#}3{#/blank#} C. You're welcome.
④Let's eat the cake. {#blank#}4{#/blank#} D. I'm 10.
⑤Thank you. {#blank#}5{#/blank#} E. Great.
