[填句补文]The acid rain(酸雨)is said to be caused by pollution from oil wells in the Gulf of Mexico. Car exhaust gases are also a problem. Local volcanic eruptions make the problem even worse. Nevertheless， with enough money and effort， researchers say that many of the problems could be solved and the rate of erosion reduced. ________.
A、The problem， however， is not just a European one.
B、That is enough to have caused some of the ancient carvings to become seriously damaged already.
C、However， the Mexican government does not have enough money to do the work， and needs to spend what money it has on the Mexican people.
D、Acid rain is how a familiar problem in the industrialized countries in Europe.
[填句补文]It‘s now socially acceptable， even fashionable， to live alone. As people get better jobs and become financially independent， it becomes possible for them to maintain a one-person household. ________. However， people who do get married are marrying at a later age and divorcing more often.
A、There‘s more pressure to get married nowadays.
B、The growing number of women with good jobs has done much to increase the number of people living alone.
C、It seems that many grown-ups today are realizing that childhood dream.
D、More and more Americans are living alone.