The door opened and ______,looking angry.A.in came Mr Smith B.came in Mr Smith

In came
首先要明确这是倒装的问题!详见下方3.
常见的完全倒装结构
1．there be 句型.
There is a mobile phone and some books on the desk.桌上有一个手机和一些书.
引导词there 还可以接appear,exist,lie,remain,seem,stand,live 等词.
There lived an old fisherman in the village.村里住着一位老渔夫.
2．用于here,there,now,thus,then + 动词 + 主语的句型中（谓语动词多为be,go,come等）.
Here comes the bus．汽车来了.
3．以out,in,up,down,off,away等副词开头,谓语动词是表示“移动”的go,come,leave等句子里.
Down fell the leaves.树叶掉了下来.
在完全倒装的结构里,如果主语是人称代词,则用正常语序.
Here we are.我们到了.
4．表示地点的介词词组位于句首,谓语动词是表示“存在”之意的be,lie,stand,exist等句子中.
South of the lake lies a big supermarket.湖泊的南边是一个大超市.
5.“表语+连系动词+主语”结构.
Gone are the days when he was looked down upon.
他被人看不起的日子一去不复返了.
常见的部分倒装结构
1.含有否定意义的副词或连词（如not,seldom,little,hardly,never,rarely,nowhere等）放在句首时.
I have never seen him before.
——Never have I seen him before.
——Never before have I seen him.我以前没见过他.
表示“刚……就……的倒装结构
Hardly had he started to leave when it began to rain.他刚要离开,天就下起了雨.
No sooner had he handed in his paper than he realized his mistakes.他刚交卷就意识到出错了.
2.副词only +状语放在句首时.
Only then did I see life was not easy.只有那时我才知道生活是不易的.
3.so作“也”讲时,引导的句子用倒装语序,表示前面所说的肯定情况也适用于另一人(或物).其句型是：So + be（have,助动词或情态动词）+主语.
She has been to Tokyo.So have I.她去过东京,我也去过.
如果对前面所说的内容,加以肯定,或不作“也”讲而只起连词作用,表示一种结果的意思,那不倒装.
--- Jack won the first prize in the contest.杰克在比赛中获一等奖.
--- So he did.确实是的.
4．Neither nor引导的句子用倒装语序,用于对前面所说的否定内容表示同样的看法.
She wo’t go.NeitherNor will I.她不走,我也不.
如果前面所说的内容既有肯定又有否定,或前后的谓语动词形式不一致时,用“It is the same with +主语”结构或用“So it is with +主语”结构.
He worked hard,but didn't pass the exam.So it was with his sister.他很努力,但没有通过考试.他妹妹也是这样.（既有肯定又有否定）
5.“so...that...和“such...that...”结构中的so或such位于句首时.
He was so excited that he could not say a word.
——So excited was he that he could not say a word.他如此激动以至于一句话都说不出来.
6．一些表示频率的副词（如many a time,often等）位于句首时.
Many a time have I seen her taking a walk alone.我多次看到她独自一人在散步.
7．表示方式、程度的副词位于句首时.
Gladly would I accept your proposal.我很高兴接受你的建议.
8．非谓语动词 + be + 主语.
Covering much of the earth's surface is a blanket of water.覆盖地球大部分表面的是水