The r-values of the insulation materials were measured.

I love playing with my R/C car.

The R/Cs are on sale today.

R-modules are an important concept in abstract algebra.

GSM-R is a communication system used in railway networks.

Some people use the term 'r-tards' as a derogatory slang for individuals with intellectual disabilities.

The r-processes are responsible for the creation of heavy elements in supernovae.

Many R&Ds are being conducted in the field of technology.

I always use the P+R when I go to the city center.

The clouds formed an R-shaped pattern in the sky.