当常数k为何值时，直线y=x与曲线y=x2+k相切？请求 出切点。

急性白血病骨髓移植治疗，哪项是错误的（）。

A.应采用HLA匹配的同胞异基因骨髓 

B.应在第一次化疗缓解后进行 

C.应及早进行，与年龄性别无关 

D.可选择自体干细胞移植 

E.异基因骨髓移植可能治愈急性白血病

某研究性学习小组为了证明某酸H_mA是强酸还是弱酸，设计了如下实验方案，请回答有关问题：

⑴当m=1时，测定0.1mol/L HA的pH值，若0.1mol/L HA的pH＞1，说明HA为     酸（填“强”、 “弱”）。

测定0.1mol/L HA的值时，pH试纸预先         用蒸馏水湿润（填“能”、“不能”）。

⑵取少量Na_mA固体溶于蒸馏水，再向得到的溶液中滴加2滴石蕊，若溶液由无色变成蓝色，证明H_mA是         酸（填“强”、 “弱”）。

若某浓度的Na_mA溶液pH=9，则该溶液中，水电离的C(H⁺)=            mol/L

⑶室温下，将pH=2的酸H_mA和pH=12的B(OH)_n等体积混合，测得混合液的pH=8。

①写出生成正盐的化学方程式                                         

②若该盐中只有一种能水解的离子，则H_mA为      酸（填“强”、 “弱”）， 离子水解的方程式为                                                 

⑷现有某浓度的H_mA溶液，蒸馏水，常见指示剂（如：石蕊、酚酞），pH试纸以及常用实验仪器，请你设计一种简单可行的实验方案，证明H_mA是强酸还是弱酸。简述实验过程、现象、结论：                                                              

                                                                。

Feasibility should be measured throughout the life cycle of system development. The scope and complexity of an apparently feasible project can change after the initial problems and opportunities are fully analyzed or after the system has been designed. Thus, a project that is feasible at one point may become infeasible later. The first feasibility analysis is conducted during the (1). The (2) represents a major feasibility analysis activity since it charts one of many possible implementations as the target for systems design. (3)  is a measure of how well the solution will work in the organization. It is also a measure of how people feel about the system. When it is determined in the later stages of the system life cycle, (4)  is often performed with a working prototype of the proposed system. This is a test of the system's user interfaces and is measured in how easy they are to learn and to use and how they support the desired productivity levels of the users. Economic feasibility has been defined as a cost-benefit analysis. The (5)  technique is a simple and popular method for determining if and when an investment will pay for itself.

空白（4）处应选择（）

A.performanc eanalysis

B.control analysis

C.usability analysis

D.interface analysis

患者，男，63岁。吸烟史35年。家属发现患者呼之不应半小时急送医院。有COPD病史20年。查体：BP150/70mmHg，浅昏迷状，球结膜水肿。双肺可闻及干湿啰音，A2（）

A.动脉血气分析

B.胸部X线片

C.心脏超声波

D.动态心电图

E.肺功能

按照现行税法规定，税收征收管理机关包括各级税务机关和海关。( )