when my first wartime christmas came

一篇英语阅读求解
When my first wartime Christmas came,I was in basic training in New Jersey and not sure if I could make it home for the holidays．Only on the afternoon of December 23 was the list of men who would have three-day passes posted．I was one of the lucky soldiers．It was Christmas Eve when I arrived home,and a light snow had fallen．Mother opened the front door．I could see beyond her,into the corner of the living room where the tree had always stood．There were lights,all colors,and ornaments(装饰物)shining against the green of a pine． “Where did it come from?” I asked．
“I asked the Gates boy to cut it,” my mother said．“I wouldn’t have had one just for myself,but when called-oh,such a rush!He just brought it in this afternoon…” The pine reached to the proper height,almost to the ceiling,and the Tree Top Krystal Star was its place．A few green branches reached about a little awkwardly(不够美观地)at the side,I thought,and there was a bit of bare trunk showing in the middle．But the tree filled the room with warm light and the whole house with the pleasant smell of Christmas． “It’s not like the one you used to find,” my mother went on．“Yours were always in good shape．I suppose the Gates boy didn’t know where to look．But I couldn’t be fussy(挑剔的)．”
“Don’t worry,” I told her．“It’s perfect.” It wasn’t,of course,but at the moment I realized something for the first time：all Christmas trees are perfect．
56．From the passage,we can infer that ______．
A．the writer spent his first Christmas during the war
B．soldiers did not all go home for Christmas during the war
C．all the soldiers had three-day passes
D．the writer could not go home for Christmas
57．When the writer got home,______．
A．it was December 23
B．it was snowing heavily
C．he found a Christmas tree in the living room
D．the Gates boy was cutting a Christmas tree for his mother
58．From this passage,we can conclude that ______．
A．the writer used to cut very beautiful Christmas trees
B．his mother didn’t like perfect trees
C．his mother didn’t want to have a tree
D．the writer wouldn’t have a tree cut by someone else
59．“All Christmas trees are perfect”,because they can remind you of ______．
A．the wartime B．the green of a pine C．the pleasant smell D．the sweet home
60．The best title for this passage would be “______”．
A．How to Choose a Christmas Tree B．How Soldiers Spent Christmas
C．The Perfect Christmas Tree D．The Christmas Without a Tree

This same thing,happening in wartime,would amount to disaster.为什么不是happened in wartime呢?