____(employ) of children under 18 is prohibited in some countries.
举一反三
- In some countries children normally go ＿ bikes.
- Developed countries， like the US， have moved the some manufactures to the developing countries. Is it true or not? （）
- Passive euthanasia (known as "pulling the plug") is legal under some circumstances in many countries.
- In some families in western countries, some children address their parents or grandparents directly by their first names.（）
- 智慧职教: In some countries, ______ and poor children are victims of child labor.