D
In my opinion, the traffic in our city is much more-convenient than it used to be.
在我看來,我們城市的交通比以前方便多了.
used to do sth “過去常常做某事,而現(xiàn)在不做了"

used to do sth. / be used to doing / be used to do的區(qū)別

used to do sth. 是“過去常常做某事,而現(xiàn)在不做了”或過去持續(xù)存在的情況,其中used只有過去式一種形式,to后面動詞用原形.如：
I used to go to work on foot, but now I usually ride a bicycle there.
我以前常常走路上班,現(xiàn)在我通常是騎自行車去上班了.
I used to live in Pudong when I was a boy.
我當(dāng)我是個男孩時我常常住在浦東.
be used to doing 是“習(xí)慣于做某事”,其中used相當(dāng)于形容詞,to是介詞,后面用名詞、代詞或者-ing形式.如：
I am already used to living in the countryside.
我已經(jīng)習(xí)慣住在鄉(xiāng)下了.
He is used to the climate in southern China.
他已經(jīng)習(xí)慣中國南方的氣候了.
be used to do 是“被用來做某事”,它是 use sth. to do (用某物做某事)的被動結(jié)構(gòu).如：
The case is used to keep the old books.
(比較：We use the case to keep the old books.)
這個箱子是用來裝舊書的
（比較：我我們使用這個箱子來裝舊書）