For Questions 21 to 22, indicate whether the statement is True or False. Give an explanation. 21. When a gas filled in a cylinder fitted with a movable piston is allowed to expand, the
work done by the gas is positive.
22. When a body is lifted, the work done by the gravitational force is positive.

Which sequence of transformations on preimage ∆abc will not produce the image ∆a'b'c'? a. reflection across the line y = x b. rotation 180° clockwise about the origin followed by a reflection across the line y = -x c. reflection across the x-axis followed by a reflection across the y-axis d. reflection across the line y = -x followed by a rotation 180° counterclockwise about the origin e. reflection across the y-axis followed by a rotation 90° clockwise about the origin

The pacific plate is an oceanic tectonic plate. how did a hot spot and the pacific plate interact to form the hawaiian islands?

Which of the following east asian contries are a peninsula? a. china b. taiwan c. south korea d. mongolia