governor control roller

one-way roller clutch

one-way roller clutch assembly

roller case material

Roller Way

Ushaped roller way

access way control

Control way

control way of main control room

inference control way

preventive control way

the Stretch Control Way

three way control valve

three-way control valve

Two-way Control

way control block

1 Matched case-control study

1︰1 matched case-control study design

1∶1 matched case-control studying