它一动不动地坐着，仿佛在沉思。

It sits ___motionless, as if in thought.

他站在那里一动不动，像个雕像。

He stood there completely ___motionless, like a statue.

那只猫一动不动地盯着窗外的鸟。

The cat sat ___motionless, staring at the birds outside the window.