Maple leafs has 3-5 pointed lobes.

Maple leaves have 3-5 pointed lobes.

Maple leaves has 3-5 pointed lobs.

Sentence 3 is written correctly in the text.

Change varieties to varietys

Change grows to grow

Change hour to our.

No change is needed in sentence 5.

Change have to has

Delete the comma after lobes.

Change their to there.

Change turns to turn.

Change Collecting to Collected.

Change sap to saps.

Change are called to is called.

Change tapping to taping.

Change is to was.

Change likes to like.

Change replace to replaces.

Change it to them.

Change use to uses.

Change new to knew.

Change for to from.

Change his to him.

Delete the comma after day.

Change returns to return.

Change to the forest to in the forest.

No change is needed.