44. A can opener is a combination of which simple machines?
A. a lever and a wedge
B. a lever and an inclined plane
C. a wedge and a screw
D.an inclined plane and a wedge

45. Which of these is an example of a wedge?
A. wheel
C. seesaw
B. spoon
D. butter knife

46. Which of the following is an example of inclined plane?
A. plier
C. scissors
B. stairs
D. nut cracker
47. In a construction site, how do workers transport mixed cement and hollow blocks from the ground floor to the 2nd floor?
A. by using a wedge
B. by using a pulley
C. by using a screw
D. by using a wheel and axle to do wOr​