为使热水器有最好的效果，需经常调节支架，使正午太阳光线直射集热板。在一年中，集热板与地面夹角的变动幅度大约是（ ）
When you say someone is ______ ，it means he／she is tired and sad．
水能流动而食用油不能流动。（ ）
选择合适的选项补全对话。
A. Nice to see you again B. I'm from the UK. C. Good morning.
D. What about you? E. Welcome back to school.
Tom：____, Miss white
Miss white: Good morning, Tom .____
Tom: Nice to see you too.
Miss white: ____we have a new friend today.
Mike: Hi, I'm Mike. I'm from Canada.____
Tom: Hi, I'm Tom.____welcome !
Mike: Thank you.
