原级：expectancy
1. They compared these changes to life expectancies calculated from death records and census data.
2. Japan is one of the leading countries in robotics and has a rapidly aging society with one of the world's longest life expectancies.
3. A survey reveals that China's more astute workers have life expectancies that average 58 years, about 10 years shorter than the national average.
4. Those who don't live on or near reservations in the West have life expectancies similar to whites'.