设二阶线性微分方程y"+p(z)y’+q(x)y=f(x)有三个特解y1=ex，，y

高危妊娠是指

A．对胎儿有较高危险性的妊娠
B．对孕妇有较高危险性的妊娠
C．对新生儿有较高危险性的妊娠
D．对孕妇、胎儿有较高危险性的妊娠
E．对孕妇、胎儿和新生儿有较高危险性的妊娠

（）analysis emphasizes the drawing of pictorial system models to document and validate both existing and/or proposed systems. Ultimately, the system models become the（）for designing and constructing an improved system.（）is such a technique. The emphasis in this technique is process-centereD. Systems analysts draw a series of process models called（）.（）is another such technique that integrates data and process concerns into constructs called objects.

（）analysis emphasizes the drawing of pictorial system models to document and validate both existing and/or proposed systems.

A．Prototyping

B．Accelerated

C．Model-driven

D．Iterative

增量预算与零基预算属于企业( )环节的方法。

A．财务预算
B．财务预测
C．财务分析
D．财务考核

市场调查中使用的最为广泛的方法是：（）

A、预测性调查

B、描述性调查

C、选择性调查

D、因果性调查

下列蛋白质中，单次跨膜的是（）。

A、带3蛋白

B、血影蛋白

C、血型糖蛋白

D、细菌视紫红质