happiness. Investing（投入）in time for parenting and raising relationships is money well spent.

28. How much would a mother earn a year if working as the Prime Minister? A. ￡30, 000. ￡142,000.

C. ￡172,000. ￡202,000.

29. The biggest challenge for most mothers is from . A. emotional demand. for work.

B. low pay

D.

B.

C. heavy workload. lack of training.

30. What is stressed in the last paragraph?

A. Mothers’ importance shows in family all year long. B. The sacrifices mothers make are huge but worthwhile.

D.

C. Mothers’ devotion to children can hardly be calculated. D. Investing time in parenting would bring a financial return. 31. What can we conclude from the study?

A. Mothers’ working hours should be largely reduced. B. Mothers should balance their time for work and rest.

C. Mothers’ labour is of a higher value than it is realized. D. Mothers should be freed from housework for social life.

D

Our planet is home to about seven billion people. Since the 1990s, population experts have predicted the number would grow to nine billion before it begins to slow down and possibly decrease.

But a new report predicts the world’s population is likely to increase to almost 11 billion by 2100. Based on the most modern statistical tools, the new report makes use of government records and considers expert predictions, including death rates, birthrates and international migration,

or people moving across borders. The report says during the rest of this century, Africa's population will grow from about 3.5 billion to 5.1 billion over the next 85 years.

John is director of the United Nations Population Division. He says that in the past, researchers thought population growth in Africa would be similar to that of other areas. They expected slower growth rates as birth control use became more widespread. But he says those ideas were wrong.

“The level of contraception use has continued to increase but slowly — more slowly than expected, and birthrate therefore has been falling less rapidly than expected, and the population therefore continues to grow