We have holidays summer.

My friend arrives at art school 1 pm.

What time do you wake up the morning?

Jane has Music lessons September.

(in on at)

in summer

Объяснение:

"in summer".

"on" is used for dates (e.g. "on Monday", "on Christmas day", "on September 10th")

"at" is used for times (e.g. "at 5:00 PM", "at midnight", "at noon")

"in" is used for weeks, months, years, and seasons (e.g. "I want to visit Canada in the winter", "I plan on going skiing in December", "I went to Spain in 2012")