（） are commonly used in mechanical-hydraulic governor（调速器） to sense engine speeds.

In using reduction gears to obtain efficient propeller speeds， （）.

According to the passage, the speeds at which a train must travel to qualify as “high-speed”______________.

High –speed rail is public transport by rail at speeds in excess of ________ km/h.

The State Railway Administration of China defines high-speed rail as a new railway line running at speeds of over 350 km/h and a dedicated railway passenger line operating at speeds of not less than 200 km/h at the initial stage.

Oligodendrocytes make myelin, a fatty substance that insulates nerve axons and speeds the conduction of impulses along nerve fibers.

New advances in wind-turbine design enable turbines to operate at lower wind speeds to convert wind ________ electricity more efficiently.

In a sense, tourism speeds up unhealthy urbanization processes and results in traffic congestion, noise and air pollution and the dumping of waste and untreated sewage.

The speeds at which a train must travel to quality as “high-speed” vary form country to country, ranging from _______ km/h to over ________ km/h.

What don’t athletes demonstrate in sports games? A: Speeds and skills. B: Interests and hobbies. C: Agility and strength. D: Striving and efforts.