310551117 lab4 lab5 lab6

[jack42611]

↓↓↓ Notice ↓↓↓

• Check your base repository and branch are belong to you.
• The PR name need to include student ID and which lab assignment
  • template: ${student id} ${which lab}
  • e.g. 0756110 lab0

↑↑↑ Notice ↑↑↑

If you ensure the notice items is done, you can remove them.

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Following section is optional, depend on you.

Description

a few message for overall goals of this pull request

Todos

• what feature to do ?
• what bug to fix ?
• what enhancement to improve ?

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@GrassLab/ta