children are likely to have less supervison at home ____was

children are likely to have less supervison at home ____was commom in the traditional family .
这个空填什么?
than/that/which/as
考研完型填空里的,那个was common 成分不理解
答案是than ,我第一个排除这个的。

"Children are likely to have less supervison at home __than__was common in the traditional family."
所有作家都这样写:例句:
(1) In the spirit in which he approaches these matters Euripides, like his friend Socrates, is much in advance of the ordinary opinion of his age. Though at times a thorough Greek in his ideas and prejudices, he displays in general more sympathy and feeling for others in the fifth century.
(2)"The “wealth effect” from rising U.S. stock prices is particularly interesting right now for two reasons. First, there has never been an advance so extreme in the price of widespread stock holdings and, with stock prices going up so much faster than GNP, the related “wealth effect” must now be bigger before. And second, what has happened in Japan over roughly the last ten years has shaken up academic economics, as it obviously should, creating strong worries about recession from “wealth effects” in reverse."
(3) Younger Scottish boys at the turn of the century wore tunics as was common in England and America. The style of tunic is somewhat different in America.
(4) From less than 6% the year before, the rate rose to more than 9%, much higher in the last 10 years. This clearly signifies a severe disturbance of the US labour market in 2009.
(5) Whitworth (rifle) chose to use a longer and more slender bullet at the time, which resulted in a bore diameter of .451 caliber, significantly smaller than the Enfield's
具有的意思.
如果同样, 我们需要使用 "as was common/ as was done": 例句:
(6) Younger Scottish boys at the turn of the century wore tunics [as] was common in England and America. The style of tunic is somewhat different than was common in America. HBC know less about tunic styles in England. We do not know how common tunics were in Scotland.
(7) The hexagonal shape of the barrel and bullet meant that the projectile did not have to bite into grooves was done with conventional rifling.
"than that" 是比较; 不是了: 例句:
(8) This was the third year in a row that employment growth in the USA has been lower than in the EU. Furthermore, the drop in US employment growth was also higher in the EU.
结论:我们学习语言,要读很多书,文章...没有捷径,没有瞎猜.读多了,我们自然知道如何使用.活学活用.