Which of these best orders the rock layers from the youngest to the oldest? (1 point)
1) layer a - layer b - layer c → layer d
2) layer a - layer d - layer b - layer c
3) layer d - layer c - layer b - layer a
layer d - layer a - layer c → layer b

Which of the choices below is one of the primary gases found in the atmosphere? a. helium b. carbon dioxide c. nitrogen d. argon

Asubject in a clinical research trial experiences a serious, unanticipated adverse drug experience. how should the investigator proceed, with respect to the irb, after the discovery of the adverse event occurrence? a. do not report the adverse drug experience to the irb since it is a common adverse experience.b. report the adverse drug experience to the irb only if there are several other occurrences.c. report the adverse drug experience as part of the continuing review report.d. report the adverse drug experience in a timely manner, in keeping with the irb's policies and procedures, using the forms or the mechanism provided by the irb.

The force needed to overcome static friction is usually less than that needed to overcome kinetic friction.true or false?