{#blank#}1{#/blank#}表示"当……时候"，既指时间点，又指一段时间，when 引导的时间状语从句中的动词可以是终止性的也可以是延续性的。

When the teacher came in, the students were talking.

When she arrives, I'll call you.

{#blank#}2{#/blank#}表示"当……时候"，仅指一段时间，从句中的动作必须是延续性的，一般强调主从句的动作同时发生， while还可以作并列连词，意为"而、却"，表示对比关系。

Lisa was singing while her mother was playing the piano.

Tom is strong while his younger brother is week.

    Hello, I'm John. I have a good friend. Her name is Gina. This is Gina's room. It's not big, but nice and{#blank#}1{#/blank#} (整洁的). Come and have a look. Her room is purple. She likes purple. What can you s{#blank#}2{#/blank#} in her room? A bed, a desk, a bookcase and a sofa {#blank#}3{#/blank#} in it. Her bed is purple, too. It's not big, {#blank#}4{#/blank#} Gina likes it. What's this on the bed? It's her schoolbag. Some books and a dictionary are in the schoolbag. I k{#blank#}5{#/blank#} Gina likes to read books. I {#blank#}6{#/blank#} (总是) meet her in the library. A desk is next to the purple bed. You can find a tape {#blank#}7{#/blank#} (播放机) and some tapes on it. A bookcase is next to the desk. Look! Four model planes are in the bookcase. Gina says the model planes are not hers. I t{#blank#}8{#/blank#} they may (可能) be her brother, Tom's. What about the radio? It's not h{#blank#}9{#/blank#}, either (也). It's her father's. {#blank#}10{#/blank#} is the sofa? Oh, it's near the window (靠近窗户). I like Gina's room very much.