Help please! Will give for the correct answer! Which of the following designs is MOST vulnerable to history effects?

Switching replication with
treatment removal

One-group pretest-posttest

One-group posttest only

Geometry: determine whether segment mn is parallel to segment kl. justify your answer. jm 6 mk 3 jn 8 nl 4

An objects motion is described by the equation d= 4sin (pi t) what will the height of the object be at 1.75 seconds?

Quadrilateral abcd in the figure below represents a scaled-down model of a walkway around a historic site. quadrilateral efgh represents the actual walkway. abcd is similar to efgh. what is the total length, in feet of the actual walkway?