prevent sb from doing sth在句中做什么成分

把prevent
sb
from
doing
sth放在句子中
prevent是谓语,sb是宾语
from
doing
sth是介词短语
作状语
修饰prevent
sb

teachers
should
prevent
his
students
from
swimming
in
the
river
in
summer
vacation.
老师应该防止他的学生们在暑假去河里游泳。