$\left(\frac{\text{1}}{\text{2}}-\frac{\text{1}}{\text{4}}\right)\times \frac{\text{4}}{\text{5}}+\frac{7}{10}=$ ____

Sarah: Hi, friends! My parents will have a birthday party for me.

Amy: Great! When is your birthday?

Sarah: It's on May 12th. It's my eleventh birthday. Will you come?

Amy: Yes！What about you, John?

John: What day is your birthday?

Sarah: It's Saturday. We have no classes.

John: OK. I'll come. Do you like sports?

Sarah: Yes, I do. I like playing football very much.

John: Good! I'll give you a surprising gift.

看图填空．

r=____

宇宙中的一切物体都是由____组成的，____是保持它们原来性质的最小微粒．人们认知的物质微粒中，空间尺度最小的是____．