How can I solve this question ?

Aknife blade is a(n) a. lever b. screw c. wedge d. inclined plane

Ablock of steel has a density of 0.29lbs per cubic inch. if the block has dimensions of 1 inch by 1 inch by 3 inches, what is its weight? a. 0.29lbs b. 0.58lbs c. 0.87lbs d. 1lbs

How does a circuit breaker protect a refrigerator? a. when the current is too high, a metal strip in the fuse melts and opens the circuit. b. when the resistance is too high , a re-settable which opens a circuit c. when the current is too high , a re-settable switch opens the circuit d. when the resistance is too high a metal strip in the fuse melts and opens the circuit