认沽期权买入开仓的风险是（）A.最小损失就是其支付的全部权利金 B.最大损失是无限的

A、B是一条直电场线上两点，相距为d，如图所示，设A点的场强为E_A，则（　　）

A．A点的场强一定小于B点场强

B．A点的电势一定高于B点电势

C．正电荷从A运动到B的过程中，电场力做正功

D．A、B两点间的电势差一定等于E_Ad

尿毒症时常见的电解质紊乱有（）。

A.高血钾

B.高血磷

C.低血钙

D.低血钾

E.轻度高镁血症

在整列车的动车中有辅助电路，拖车中没有辅助电路。

要根据原料质地老嫩和形态大小灵活调整好油温。( )

DOM is a platform-and language- (41) API that allows programs and scripts to dynamically access and update the content, structure and style of WWW documents (currently, definitions for HTML and XML documents are part of the specification). The document can be further processed and the results of that processing can be incorporated back into the presented (42) . DOM is a (43) -based API to documents, which requires the whole document to be represented in (44) while processing it. A simpler alternative to DOM is the event -based SAX, which can be used to process very large. (45) documents that do not fit info the memory available for processing.

（43）是（）

A.table

B.tree

C.control

D.event