D．They don't like each other．

（2）What are the advantages of Paris mentioned in the article？　 　

a．Louvre Museum

b．Free access to museums

c．More outdoor attractions

d．Better wines and perfumes

A．ac

B．cd

C．acd

D．bcd

（3）Lonely Planet recommends these two pairs of cities because　 　．

A．they are not expensive to visit

B．they are best known to the world

C．they are always enemies between each other

D．they are close but different in many aspects

13．（8分）Age plays a major part in people who are infected with cold，ie，in people who suffer from cold infection．A study done by University of Michigan，has shown information that seems to be true for the general population．Babies are the most cold infected group，generally more than six colds in their first year．Boys have more colds than girls up to the age of three．After three，girls are easier to get infected with cold than boys，and teenage girls get three colds a year to boys'two．The general cold infections continue to get less into adults．Elderly people who are in good health have as few as one or two colds every year．One interesting thing is found among people in their twenties，especially women，who show a rise in cold infection，because people in this age group are most likely to have young children．

The study has also found that economy plays an important role as well．With more and more income，the frequency at which colds are reported in the family is getting lower and lower．Families with the lowest income usually suffer about a third ally forces people to live in rooms more crowded than rooms owned by richer people，and the crowding usually leads to more chances for the cold virus to travel from