补全对话
Sam: Hello, {#blank#}1{#/blank#}is Sam speaking.
Bobby: Hello, Sam. This {#blank#}2{#/blank#}Bobby.
Sam: {#blank#}3{#/blank#}are you today?
Bobby: Not so {#blank#}4{#/blank#}.
Sam: What's the matter?
Bobby: I have a cough and a {#blank#}5{#/blank#}.
