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Units of time such as week and larger units use “in.” Parts of the day can use “in” ([the] afternoon, [the] morning) or “at” (night)(noon, daybreak, sunset, midnight, etc.).
Answers: 1. on 2. in
at 4. on 5. in
6. on 7. in 8. at (Note: “at night” is an exception to the rule. It’s an idiom.)
9. at 10. in
Americans speak of living (or being) “on” a street, while British people use “in” a street. “ On” is used for floors in a building.