This movie is R-rated, so children must be accompanied by their parents.

The company invests heavily in R&D to drive innovation.

I used 10 kwh of electricity last month.

The three R's are reading, writing, and arithmetic.

The R.A.A.F. is responsible for protecting Australian airspace.

The R.A.F. is the aerial warfare force of the United Kingdom.

The red blood cells carry oxygen to all parts of the body.

The R.C. provides humanitarian aid to those in need.

The R.C.Ch. is one of the largest Christian denominations in the world.

R.I.P. my dear friend.