他们一登上滩头阵地就意外地遭到两面夹攻.用英语怎么说？

他们一登上滩头阵地就意外地遭到两面夹攻.

They were attacked unexpectedly from both sides as soon as they landed at a beachhead.

they

pron. 他/她/它们，人们，大家，政府，当局，她们；

例句
The storms had abated by the time they rounded Cape Horn.
他们绕过合恩角时，暴风雨已经减弱。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

attacked

v. 攻击，进攻，抨击( attack的过去式和过去分词 )，非难，损害；

例句
He was attacked by wild animals...
他遭到野兽的袭击。

unexpectedly

adv. 未料到地，意外地，竟，居然，骤然；

例句
Against the run of the polls, the Socialist Workers' Party won Sunday's general election by an unexpectedly large margin.
工人社会党逆转乾坤，出乎意料地以较大优势获得了星期天大选的胜利。

from

prep. （表示时间）从…，（表示原因）因为，（表示来源）来自…，（表示分离）与…分离[隔开]；

例句
...an abortive attempt to prevent the current President from taking office.
企图阻止现任总统连任的失败尝试

both

adj. 二者，两者都；pron. 二者；adv. 二者，二者都；conj. 不仅…而且…，…和…都；

例句
The gym can be used by both able-bodied and disabled people.
这家健身房健全和残障人士都可使用。

sides

n. 侧，面( side的名词复数 )，方面，侧面，一面；

例句
The warring sides have agreed on an unconditional ceasefire...
交战各方已经同意无条件休战。

as

adv. 同样地，一样地，例如；prep. 作为，以…的身份，如

例句
As far as I can recall, Patti was a Smith.
我记得帕蒂是姓史密斯的。

soon

adv. 立刻，马上，一会儿，不久，快，宁愿；

例句
The minister advised him to leave as soon as possible...
部长建议他尽快离开。

landed

adj. 拥有大量土地的；v. （使）登岸( land的过去式和过去分词 )，降临，使陷于（困境），使不得不应付；

例句
The allies landed thousands of airborne troops.
盟军空投了数千人的空降部队。

at

prep. （表示位置）在，在（某时间或时刻），以，达， 向，朝；n. 阿特（老挝辅币单位，100 阿特 = 1 基普）；

例句
Prices start at £13.95 a metre for printed cotton...
印花棉布以每米13.95英镑的价格起售。

beachhead

n. 滩头阵地，滩头堡；