可直接给动物注射用于预防毒素中毒的物质是（） A.内毒素 B.外毒素 C.干扰素 D
题型：单项选择题 A1型题
问题：
可直接给动物注射用于预防毒素中毒的物质是（）
A.内毒素
B.外毒素
C.干扰素
D.类毒素
E.抗生素
题型：单项选择题 A1型题
阅读下面短文，根据所读内容在文后第1至第5小题的空格里填上适当的单词或短语。注意：每空不超过
3 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 its 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 advantage 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 advantages, however, have not prevented host families form worrying. On one hand, some host families
are losing their unique selling point. The problem is that the majority of hosts in big cites, now generally single
and young, have less times available for students but the selling point for host family accommodation is
communication practice. One 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 making living conditions better, including broadband 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: 1. ______________
