单项选择题
Manually operated band brakes may be fitted and （） will have a brake arranged to fail-safe.
A.the drive pump B.the drive motor C.the warp end D.the purchase
单项选择题 The （） is used for hauling in or letting out the wires or ropes.
单项选择题 （） may be fitted for operating the derrick topping lift (the wire which adjusts the derrick height).
单项选择题 （） provides the head or pressure to supply the domestic water where required.
