Read the passage. Circle the best answer A, B, or C to each of the questions

Family life has been changing across some Southeast Asian countries over the past few decades. Many years ago, most of teenagers lived with their families, spending several hours at school and the rest of time at home enjoying family atmosphere. Besides their studying, adolescents could do some housework like doing the dishes, cooking, taking care of younger children or supporting their family business. These days, studying takes up such a lot of time that they cannot help much with household chores and sometimes they even hardly have time to relax. This can lead to suffering worse health and losing the bond with their family. In families with higher income, parents are often so busy with their work that they send their children to private boarding schools, and the time these students share with families is shortened more and more. In many cases, high-schoolers meet their siblings and parents at weekends only. It’s believed that there are some advantages to live and study in academic places, but other benefits that schools are unlikely to provide should be taken into consideration. For example, these young learners can learn a lot from their parents about social skills and doing domestic chores. On one hand, some people think that teenage students prefer to have privacy than to be controlled by adults, which may be true. On the other hand, nothing can compare or replace the parents’ affection in terms of nurturing their children’s souls and their behaviours. Changes often bring positive results but how people consider what is important to maintain and preserve is worth thinking again.

Scientists can ___________ carbon footprint based on daily usage of each family.