Suppose that in the year 2015 the number of births is temporarily high. How does this baby boom affect the price of babysitting services in 2020 and 2030?(Hint:5-year-olds need babysitters,whereas 15-year-olds can be babysitters.)
举一反三
- The survey among 25-65 year olds focused on________.
- How old was the baby? A: 15 months B: 16 months C: one year old D: one year and a half old
- The number of students participating in online courses varies . A: year to year B: year and year C: year by year D: year on year
- A number of high buildings have arisen _______ there was nothing a year ago but ruins.
- A number of high buildings have arisen______ there was nothing a year ago but ruins.