If we don't defend our country, Saruman will take it by force.如果不捍卫自己国家，萨鲁曼就会来掠夺

by force用武力或强迫手段

He was cleared out of the office by force.

他被强行赶出办公室。

The soldiers took the prisoners away by force.

士兵们强行把犯人带走了。

Orcs are roaming freely across our lands.半兽人在我国横行霸道

roam，stroll，wander，ramble这些动词均有“徘徊、漫游”之意。

roam常指在广阔地方以自得其乐的愉快心情作无固定目标的漫游。

stroll常指无明确目的他悠闲而缓慢地漫游。

wander指无目的地到处徘徊或闲荡。

ramble一般指走走停停，心情愉快，步履轻松。