(1)1.we have a growing population and we are______in need of more and more food.A.so B.hence c.however D.thereforehence,however,therefore,thus等表示结果的词有什么区别呢?

however表示结果，是adj，意为“无论如何” “可是” “然而”等
hence ............adj，意为 “从此” “因此” “所以”therefore .........adj, 意为“因此” “所以” “为此”
thus...............sdj，意为“这样” “因而”“如此”“至此程度”

B
hence 因此

D a,b,选项是连词,本题已有表示连词的and,所以只能有副词therefore
hence,thus,therefore,意为因此,前两个连词,however意为然而,表转折,也做连词

1. 【书】因此;由此
hence
This is a gold necklace, hence it is expensive.
这是根金项链,因此很贵。
2. 【书】从现在;从这时起;从此
The railroad will open at the end of the decade, two years hence.
这条铁路本世纪末通车,离现在还有两年时间。
3. 【书】从今世;从此生
go/depart hence
去世
4. 【书】从这地方;离此地
however是然而带有转折的意思
比如He is good,however we need the best.
thus
1. 如此,这样,以此方式
They told her to water the flowers every morning, and she did it thus.
他们吩咐她每天早晨浇花,于是她照办了。
2. 到如此程度
3. 因此,从而
He didn't work hard. Thus he was fired.
他工作不努力,因此被解雇。
therefore
因此,从而
He didn't work hard. Thus he was fired.
他工作不努力,因此被解雇。