下列类型的数据不可以存储在可变型变量中的是( )。A．整型 B．字节型 C．单精度

临床试验单位有关临床试验的资料应当至少保存（）.

A.1年

B.3正

C.5年

D.10年

E.20年

In Wiltshire, England, volunteers are being sought to visit a nature protection area to count the butterflies living there and on surrounding fields. The project is promoted by an environmental protection organisation，which has contributed to improving the living environment for wild animals. Recently, the organisation has issued an appeal to help it observe environmental changes based on the record of butterflies and protect the environment.

In the area, the local people have planted many special flowers with the help of the organisation, aiming to see whether these flowers will interest the rare and beautiful butterflies. The Project officer Sarah Marshall says, “It will be a suitable habitat for butterflies. They are great ‘indicator species’ as they are easily affected by climate changes so they make a brillian early - warning system for the environment.” She also points out that volunteers are needed to recourd the number or species of butterflies，and based on the change happening to the butterflies, the hidden environmental problems in the area can be found out in time.

The organisation is seeking volunteers to help monitor butterflies from April through to September. They will walk a fixed route and record the different butterflies they encounter along the way.Each visit should take no more than two hours, and each volunteer is expected to visit once a month to count the wildlife. “Staff will provide back up, so if the weather is poor on the day you are to visit（butterflies don’t like to fly in the rain, wind or if it’s too cloudy) we can have someone else do your job,” Sarah points out.

No previous experience is necessary as training and support will be provided，but a keen interest is essential. If you are interested, P1ease contact Sarah on (0l380) 725670，ext 278, email sarahm wiltshirewildlife. org

小题1:According to Paragraph l， what is the purpose of the Project?

A．To appeal to more visitors.

B．To protect the environment.

C．To control butterfly population.

D．To expand the area for wildlife.小题2:Many special flowers have been planted in Wiltshire to           .

A．warn people of wildlife extinction

B．appeal more tourists to be involved in

C．attract many unusual and beautiful butterflies

D．improve the economic conditions of local people小题3:Butterflies are called “indicator species” because              .

A．they can provide support for visitors

B．they can give information to other species

C．they are not easily found out in their habitats

D．they are very sensitive to environmental changes小题4:What is the text mainly about?

A．Visitors are being trained to identify butterflies.

B．Wildlife areas are being protected by butterflies.

C．Volunteers are being needed to count butterflies.

D．Organisations are being put up to protect butterflies.

10个月婴儿，不会笑，不能坐，偶尔有全身性抽搐，尿霉臭味，面色苍白，毛发黄褐色，四肢肌张力增高，此患儿最可能的诊断是（）

A.先天愚型

B.佝偻病

C.苯丙酮尿症

D.缺乏维生素B₁₂

E.呆小病

一般来讲电压和电流结合起来，会对人体造成伤害。为了防止对人体的伤害，根据人体允许电流，一般规定安全电压为110V以下。