I'll be interested in seeing what you come with. So far, run into an error:
```
all.deltas = rep(NA, 10)
for (c in 2:10) {
  glm.fit = glm(wage~cut(age, c), data=Wage)
  all.deltas[i] = cv.glm(Wage, glm.fit, K=10)$delta[2]
}
```
`factor cut(age, c) has new levels (18.9,49.5], (49.5,80.1] `