Please correct my English.?

I'm studying English.  Please let me know if there are any errors in the sentence I made.

1) More people have a little cold because it has suddenly become cold.

2) I definitely mustn’t be absent from school because my attendance rate is bad.3) I couldn’t even write the alphabets last year, though I am at the A1 level now. (*A1: test results)4) I was so tired yesterday that I couldn’t even eat.5) My mother told me off because I left the water running while I was brushing my teeth.6) My room is full of trash because I have not cleaned it up for a month.7) What’s the matter? You suddenly started laughing.8) It’s a typical spring day with cherry blossoms blooming.9) I thought I had lost my key but I found it in my bag after looking for it carefully.10) A: What kind of Japanese food do you like?      B: Let me see. I like sushi, tempura and such.11) I went shopping near the station and dropped by the new coffee shop on my way home.12) Anuradha looks happy. There must have been something good to her.13) No teacher is as kind as the ones in our school.14) I don’t feel well when I come to school without eating breakfast.15) Tan wants to talk to the cute girl next class so badly.Thank you in advance.