Shelves
Mitochondria
cargoes or cargos
sheep, it doesn't change.
Children or kids
Crises -- pronounced krahy- - seez
The plural of activity of activities.
oxen - eg. a team of oxen pulled the plough
Successes is the plural form of the noun success.
phenomenons; for example, they were hit with many phenomenons. :) hope this helpss :D
The plural of calculus is generally "calculi." The word "calculuses" is also a plural, but very rare.
The word "sew" is a verb, not a noun. There is no plural for sew.