WASHINGTON-Laura Straub is a very worried woman . Her job is to find families for French teenagers who expect to live with American families in the summer . It's not easy , even desperate . "We have many children left to place :40 out of 75," said Straub , who works for a Paris-based foreign - exchange programme called LEC. When exchange programmes started 50 years ago , family life was more accommodating . For one thing , more mothers stayed home . But now , increasing numbers of women work outside the home . Exchange-student programmes have struggled in recent years to sign up host families for the 30,000 teenagers who annually come from abroad to spend academic year in the prefix = st1 /United States, as well as the thousands more who participate in summer programmes . School systems in many parts of the US, unhappy about accepting non-taxpaying students , have also strictly limited the number of exchange students they accept . At the same time , the idea of hosting foreign students is becoming less _ . In searching for host families , who usually receive no pay , exchange programmes are increasingly broadening their appeals to include everyone from young couples to retirees . "We are open to many different types of families," said Vickie Weiner , eastern regional director for ASSE, a 25- year -old programme that sends about 30,000 teen-agers on academic -year exchange programmes worldwide . For elderly people , exchange students "keep us young -they really do ," said Jean Foster , who is hosting 16-year -old Nina Porst from Denmark. From the passage we can learn that at the beginning of the exchange programmes ,_.
all the families cold host foreign students only young couples could host foreign students only those who were retired could host foreign students those who were not too old could host foreign students