让太阳光通过硬纸板上很小的三角形小孔,在地面上将观察到一个圆形的光斑,这说明光在空气中是沿 传播的.使硬纸板与地面之间的距离增大10cm,可以发现光斑的形状不变,光斑的大小 (选填“变大”、“变小”或“几乎不变”). 答案:直线 几乎不变情景对话。1. 当我们表达“今天是2月15日”时,应说:
[ ]A. Today is February fifteen. B. Today is fifteen February. C. Today is February fifth. D. Today is February fifteenth.2. 当我们想问别人“你旅行愉快吗?”时,应说:
[ ]A. Are you a good trip? B. Do you have a nice trip? C. Is it a good trip? D. Are you happy for your trip?3. 当我们想问丹尼“你的尾巴发生了什么事?”时,应说:
[ ]A. What happened to your tail? B. What's your tail? C. Where's your tail? D. How's your tail?4. 当别人对你说“Thank.或Thank you.”时,你应回答:
[ ]A. That's right. B. You're welcome. C. You're right. D. Thank you.5. 当你想说“我非常想念你”时,应说:
[ ]A. You miss me very much. B. I like you very much. C. Thank you very much. D. I miss you very much.