Masami chose his brushes arranged his paints set up his easel and ...

[segrsyd]

Masami chose his brushes arranged his paints set up his easel and began his
  painting.
 
  Add commas to the following sentences where necessary. If the sentence is correct,
  do nothing to it.

Question 2

To maximize its jump the cow went on a diet and then it researched when the
  moon would come closest to earth.
 
  Add commas to the following sentences where necessary. If the sentence is correct,
  do nothing to it.

[sokh]

Answer to Question 1

Masami chose his brushes, arranged his paints, set up his easel, and began his painting.

Answer to Question 2

To maximize its jump, the cow went on a diet, and then it researched when the moon
would come closest to the earth.

[segrsyd]

Gracias!

Excellent