focus（）
A: on
B: in
C: to
D: ut
A: on
B: in
C: to
D: ut
A
举一反三
- The government is going to ____ the question of homeless people. A: focus in B: focus on C: focus to D: focus with
- Catherine said she had eaten nothing ________ she was not hungry. A: ut that B: and C: that D: ut
- 6.The children’s faces are badly________in the photograph. A: focused B: out of focus C: in focus D: without focus
- 下列哪种序列相关可用DW检验(vt为具有零均值,常数方差且不存在序列相关的随机变量)( )。 A: ut=ρut-1+vt B: ut=ρut-1+ρ2ut-2+…+vt C: ut=ρvt D: ut=ρvt+ρ2 vt-1 +…
- 承压设备制造常用的无损检测方法主要包括哪些检测方法＜br＞（） A: RT、UT、MTA、RT、UT、MT B: RT、UT、MT C: RT、UT、MT、PT、ET
内容
- 0
如果模型yt=β0+β1xt+ut，（ ）则说明不存在随机误差项自相关问题。 A: cov(xt，ut)=0 B: cov(us，ut)=0(t≠s) C: cov(xt，ut)≠0 D: cov(us，ut)≠0(t≠s)
- 1
下列哪个序列相关可用DW检验（vt为具有零均值，常数方差且不存在序列相关的随机变量）（ ）。 A: ut＝ρvt t B: ut＝ρut－1+ρ2ut－2+…+vt C: ut＝ρut－1+v D: ut＝ρvt+ρ2 vt-1 +…
- 2
This article will two medicines that have changed people’s lives. A: focus in B: focus on C: focus to
- 3
makes（） A: up B: to C: so D: ut
- 4
应用GB/T19779计算油船油量时，计量空高可采用公式（）对油船进行横倾修正。 A: UT=（Um/cosθ）±Z×tanθ B: Um=（UT/cosθ）±Z×tanθ C: UT=（Um/tanθ）±Z×cosθ D: Um=（UT/tanθ）±Z×cosθ