许多物理过程都是有方向性的，例如：水总是由高处向低处流动。根据你所学物理知识，再

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阅读下面短文,根据所读内容在文后A到J的空格里填入一个单词.注意：每空仅填一个单词.
Host family accommodation, or living with host families, remains popular among language travel students for its advantages. These days, host families are trying to offer more in terms of quality, for they still have something to worry about.
Host family accommodation is often seen as the number-one choice for advantages in language study, cultural communication and cost of living. Staying alongside host families enables students to get enough practice for the short time of their studying so that their language acquisition is likely to become faster. Living in host families also has the advantages for students of being able to spend a lot of time communicating with their “host parents”, and get to know the local way of life, people and culture. Another advantage is that host family accommodation can sometimes be the least expensive. It attracts students for it ensures them a family type of living at a low cost.
The advantage, however, have not prevented host families from worrying. On one hand, some host families are losing their unique selling point. The problem is that the majority of hosts in big cities, now generally single and young, have less time available for students, but the selling point for host family accommodation is communication practice. On the other hand, students’ expectations have risen. They are becoming more demanding and asking for more than ever from their accommodation, as they come mainly from high socio-economic groups in their own countries.
To get out of the difficult situation, host families are now making efforts to improve the quality of service. They are trying to make living conditions better, including broadband（宽带） Internet service, private bathroom, and access to plenty of hot water for long showers. They are also providing students with structured family activities.
It is believed that host family accommodation will keep the popularity vote with language travel students.
Title: Host Family Accommodation 

Theme

Host families are improving the accommodation __16____

Language study	possibly becoming ___18_____
Cultural communication	communicating with __19____
	Knowing the local way of life, people and culture
cost of ___20___	Being least expensive sometimes

                                        

____17__

 
 

___21_____		Loss of selling point	Hosts’ having less time for students
		Rise in ____22____	Students’ becoming more demanding

____23____

Service quality improvement	____24____ living conditions
	Organizing structured familyactivities

____25____

Host family accommodation will keep the popularity vote with students.

Keys: