聪明的你能够由小长大，其根本原因是（　　）

6C（s）+5H₂（g）+3N₂（g）+9O₂（g）═2C₃H₅（ONO₂）₃（l）△H₁

2H₂（g）+O₂（g）═2H₂O（g）△H₂

C（s）+O₂（g）═CO₂（g）△H₃

则反应4C₃H₅（ONO₂）₃（l）═12CO₂（g）+10H₂O（g）+O₂（g）+6N₂（g）的△H为（   ）

抛物线$y=x^2$上的任意一点到直线$x-y-2=0$的最短距离为（   ）

Ladies and Gentlemen，

    Thank you for coming to attend the graduate ceremony.First of all，I'd like to 1 all the students who are here today.I remember  2 all of you when you were just starting Grade 7 at this school.You were so full of energy and thirsty 3 knowledge.And some of you were a little difficult to deal with！But today，you've all grown up so 4 and I am so proud of you.

    Although you've all worked very hard over the last three years，none of you did it 5 .I hope you'll remember the important 6 in your lives who helped and supported you.Please consider what they've done for you.Never 7 to be thankful to the people around you.

    Lastly，the end of junior high school is the beginning of a new  8 .You will have many difficult tasks 9 you.You'll make mistakes along the way，but the key is to 10 your mistakes and never give up.But along with difficulties，there will also be many  11 things waiting for you.Learn the new things，and you'll have the ability to make your own choices.Choose  12 and be responsible for your decisions and actions.  13 you have to go your separate ways now，I hope that you'll come back to visit our school in a few years' time.As you 14 on your new journey，you shouldn't forget where you came form.The future is 15 .

    Good luck and hope to see you again sometime soon！