Please help me ASAP 16 points

Which research model refers to the study of an individual, group, or community over a predetermined period? a. cross-sectional model b. sectional model c. cross-sequential model d. longitudinal model

Which of the following guidelines should be followed if you have a large spill that is dangerous or beyond your ability to clean up? a) call emergency authorities b) try to keep it quiet so nobody panics c) if the material is flammable, get several buckets of water to dilute it with d) wipe up as much as you can with appropriate rags

Arecent challenge to the european union created by a member state is?