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【多选题】
对浴盆曲线描述正确的是（）。A.
早期故障阶段这一阶段的产品故障主要是设计与制造中的缺陷
B.
偶然故障阶段产品故障率可降至一个较低的水平，且基本处于平稳状态，可以近似认为故障率为常数
C.
耗损故障阶段产品故障率迅速上升，很快出现产品故障大量增加或报废的现象
D.
耗损故障阶段是产品的主要工作期间
E.
规定的允许故障率越高，产品的使用寿命越少
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举一反三
【单选题】The man went to prison, but the two boys______with a warning.
A.
took off
B.
got off
C.
kept off
D.
set off
【单选题】从图2—1所示灰铸铁件上的不同部位切取l、2、3号标准拉力试棒。经测试后,三者的抗拉强度应符合( )。
A.
σ3＞σ2＞σl
B.
σ1＞σ2＞σ3
C.
σl＞σ2＜σ3
D.
σl＝σ2＝σ3
【单选题】They kept trying, and their efforts finally _______.
A.
make it
B.
paid off
C.
are made it
D.
are paid off
【简答题】请根据视频内容回答word文档中的问题。 C1 Pass 5 Celebrating St. Lucia's Day.mpg Celebrating St. Lucia's Day.docx
【单选题】All the mobile phones must be ______ during the meeting. [ ]
A.
kept fit
B.
kept quiet
C.
kept off
D.
kept away
【单选题】Brian kept __ off the pizzas, so he lost the race. [ ]
A.
to fall
B.
fell
C.
falling
D.
fall
【单选题】He will stop showing off, if no notice _____ of him.
A.
is taken
B.
will be taken
C.
takes
D.
has taken
【单选题】The rain has stopped. Please _____ your umbrellas. [ ]
A.
put away
B.
put off
C.
kept up
D.
kept on
【单选题】He had something urgent to do , so he asked___. A.have a day off B.having a day off C.to have a day off D.to have a day away
A.
have a day off
B.
having a day off
C.
to have a day off
D.
to have a day away
相关题目：
【简答题】请根据视频内容回答word文档中的问题。 C1 Pass 5 Celebrating St. Lucia's Day.mpg Celebrating St. Lucia's Day.docx