bat（t）=打击（to beat）

词义：n.1.球拍（棒）（to hit or beat）

a baseball bat 棒球球棒

2.蝙蝠

combat=com-+bat（打击 to beat）

词义：n.1.打仗；战斗

（fighting or a fright,especially during a time of war）

He was killed in combat.

他在战争中阵亡。

2.v.战斗；斗争

We combat with them for our rights.

为争取我们的权益，我们跟他们作斗争。

debate=de-+bat（打击 to beat）+e

词义：n.辩论（an argument or discussion）

There had been much debate on the issue of childcare.

人们对儿童保育问题议论纷纷。

v.辩论

（to discuss sth.,especially formally, before making a decision or finding a solution）

The question of the origin of the universe is still hotly debated(=strongly argued about) by scientists.

关于宇宙起源的问题，科学家仍进行着激烈的辩论。

battle=batt（打击 to beat）+-le

词义：n.斗争；战斗

（a fight between armies,ships or planes, especially during a war）

to be killed in battle 阵亡

v.斗争

Both teams battled hard.

两队拼得很厉害。