项目施工准备阶段的成本计划是以项目实施方案为依据，采用（）编制而形成的实施性施工成本

破伤风抗毒素过敏试验阳性病员的处理是

A．不能注射

B．将破伤风抗毒素分四等份，分次注射

C．将破伤风抗毒素剂量逐渐递增，分次注射

D．将破伤风抗毒素剂量逐渐递减，分次注射

E．将破伤风抗毒素分五等份，分次注射

---What _____useful book !

---Yes, it is. But I find it ______ difficult for me to read.

A．an, very

B．a, too

C．an, too

D．a, quite

当前盘当前目录下有数据库：学院.dbc，其中有“教师”表和“学院”表。

有SQL语句：

SELECT主讲课程，COUNT(*)FROM 教师 GROUP BY 主讲课程

该语句执行结果含有记录个数是（）。

A．3

B．4

C．5

D．6

左归丸治眩晕，不应具备的症状是：

A．四肢不温
B．舌质红
C．脉沉细
D．五心烦热
E．盗汗口干

Consider two markets; one has a Herfindahl-Hirschman Index (HHI) of 50, while the other has a four-firm concentration ratio equal to 2%. Which of the following statements most accurately describes these two markets（）

A. Both of these markets are monopolies.

B. The market with the HHI equal to 50 is very competitive, while the other market has low competition.

C. Both markets are highly competitive.