Sustainable development of the rainforest is probably necessary. Sustainable development has been recommended. Everyone deserves access to health care. Categorical - it uses 'everyone' and simple present. Many people believe that everyone deserves access to health care.
Students learn more when they study in groups.
Categorical - it uses simple present and no modifiers. Students seem to learn more when they study in groups. In many cases, students learn more when they study in groups. Countries with more guns have more gun crime. Categorical - it uses simple present and no modifiers.