某人工作半年的工资是5200元和一头牛，工作四个月他被辞退，辞退时获得的工资是2

VVI起搏器植入术后，右心室心尖部起搏，以下心内膜电极定位描述正确的是（）

A.起搏阈值在脉宽0.5ms的条件下不应＞1mV，2mA

B.R波幅度＞5mV，斜率（dv/dt）＞0.5V/s

C.侧位X线透视电极尖端朝向胸骨侧

D.心电图Ⅱ、Ⅲ、aVF导联QRS波群直立

E.心电图Ⅱ、Ⅲ、aVF导联QRS波群倒置

Most of us found ______ difficult to finish the work in such a short time.

A．this

B．which

C．what

D．it

隧道支护与围岩之间存在空洞时，会导致围岩松弛，使支护结构产生( )。

A．拉应力
B．压应力
C．剪应力
D．弯曲应力

对被收容教养的未成年人应坚持( )的原则。

A．教育为主、惩罚为辅

B．惩制为主、教育为辅

C．教育与惩罚并重

D．重在教育

Challenges to implementing a discretionary fiscal stimulus in a timely manner are least likely to include the:（）

A. government payments for unemployment benefits.

B. need to convince lawmakers that action must be taken.

C. inability of policymakers to forecast a recession precisely.