电磁透镜成像时，物点固定不变（物距不变），在保证成像清晰的条件下，像平面沿透镜主轴可移动的距离，叫做（ ）。
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1、下列关于session的说法错误的是( )。
A. 在访问网站时，服务器端自动分配一个session对象给用户使用
B. 对于同一个用户，当网站的页面改变时，用户使用的session也会改变
C. session负责保存同一个客户端一次会话过程中的一些信息
D. session能够跨页保持
2、通过()方法可以将内容保存在session中。
A. session.setAttribute(Stringname,Objectobj)
B. session.getAttribute(Stringname)
C. session.setValues(Stringname,Objectobj)
D. session.getValues(Stringname)
4、下列关于sessionld的说法错误的是()。
A. 对于不同的客户来说，每个人的session是不同的
B. 对于每一个session，服务器端都有一个sessionld来标识它
C. 在第一次访问时，服务器端就给session分配了一个sessionId
D. 在客户端访问下一个页面时，不会将sessionId传递给服务器端
Which is the correct paragraph leader?...........However, in the 1980s the debt crisis and the ensuing contraction of budgets prompted a re-appraisal of public sector provision. Donors began lobbying for the restructuring of public services; by the 1990s, they were demanding full-scale privatisation. However, implementation of such reforms has been slow.
At the same time, the World Bank increased its support for private investment in utilities through its International Finance Corporation and its Multilateral Investment Guarantee Agency.
B. One of the chief reasons: lack of interest from private investors.
C. Hence, African countries have been caught in a terrible bind. Not only has donor financing of public investment declined but also private investment has followed suit.
D. When countries in sub-Saharan Africa became independent, the state dominated the provision of utilities.
E. Thus, many governments have had to re-align their expectations.
F. The initial hopes for privatisation were so high that donor spending on infrastructure fell in the expectation that the private sector would take up the slack.
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