4. self-study, extra curricular activities

e.g. A large number of students in China have to do self-study at night, so extra curricular activities have go give way to studies.

5. post a threat to

e.g. The development of cities has posed a threat to heritages sites, but the government has no idea whether to protect or demolish these constructions.

6. face-to-face communication, enrich our social lives, have a direct impact on

e.g. Internet can enrich our social lives, but we should not ignore/ neglect face-to-face communication, because this has a direct impact on social relationships.