Put the verbs in brackets into the correct tense​

1.   dental   students receive (present simple - мн.число) their education in specialized dental   schools.  2.   in russia a training course for certified dental   students lasts (present simple - ед.число) five  academic years.3. apart from general medical disciplines, the four principal divisions of  dentistry are recognized (страдательный залог в present simple) in curricula in russia.4.   entry to a dentistry department depends (present simple - ед.число)on the resul ts of com-petitive examinations.5.  for hundreds of years people  believe (present simple -мн.число) that tooth decay is caused (страдательный залог в present simple) by a worm in the teeth.6. short courses are offered (страдательный залог в present simple) regularly to dentists to keep them informed  of the new developments in dentistry.7 .   dentistry is considered (страдательный залог в present simple)well-paid and secure employment in great   britain.8.   study of basic medical   and dental   subjects  is closely interconnected _(страдательный залог в present simple) with clinical dentistry.9.   anatomy , biochemistry and physiology are studied _(страдательный залог в present simple) at medical   uni-versities.10.   before starting to work wi th patients in clinics, students are taught _(страдательный залог в present simple) the techniques on phantom heads.11.   doctors  look (present simple - мн.число) for new ways to help patients.12.   medical   science makes (present simple - ед.число) a lot of progress in recent years both  in treatment and diagnosis.13.   many simple measures are taken (страдательный залог в present simple) to prevent dental   diseases.1 4.   preventive care aims (present simple - ед.число)at the two major tooth troubles:   caries and  gum diseases.15.   preventive orthodontics is (present simple - ед.число) another aspect of early treatment.