Harbin Photography Technology Analysis Recruitment

Solution: Solution: A. Liquid can transmit constant pressure, with small force in small area and large force in large area.

B, as shown, make a power arm and a resistance arm. The power arm is smaller than the resistance arm and is a laborious lever.

C. Under the condition of constant pressure, the wide wheel of forklift increases the stress area and reduces the pressure on the ground.

D, the uneven pattern on the forklift wheel surface is to increase the roughness of the contact surface to increase the friction force under the condition of constant pressure.

So choose B.