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【单选题】
在焊接过程中焊条药皮的主要作用是（ ）。
A.
保护作用
B.
助燃作用
C.
升温作用
D.
降温作用
拍照语音搜题，微信中搜索"皮皮学"使用
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【简答题】听下面一段对话，回答第1-4题。 1. How many people are in the woman's family? A. Three B. Four C. Five 2. What did the children think about having dinner together at home? A. They thought it was funny B. They dislik...
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【简答题】根据对话情景选择恰当的选项,其中有两项是多余的。 A. And we had a very wonderful time. B. How long did you stay there? C. Where did you go last week? D. In two days. E. What is it famous for? F. Did you take a lot of photos? ...
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【单选题】听力原文：W: Your survey sounds very good. How many people filled it in? M: I gave out 120 copies and I got 70 back. W: That's a very high rate of return. Who did you give your questionnaires to? M: I gave...
A.
His schoolmates.
B.
People of different ages.
C.
People in the hall of residence.
D.
His friends at the university.
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【多选题】How did the speaker feel when she first came to the college?
A.
homesick
B.
isolated
C.
rich
D.
in awe of everything and everyone
E.
happy with many new friends
F.
constant social anxiety
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【单选题】两个稳压二极管，稳压值分别为7V和9V，将它们用于图所示电路。设输入电压 U1值是20V，则输出电压 U0为（）
A.
0.7V
B.
7V
C.
8V
D.
20V
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【单选题】两个稳压二极管,稳压值分别为7V和9V,将它们用于图 所示电路。设输入电压 U1值是20V,则输出电压 U0为( )。
A.
0.7V
B.
7v
C.
9v
D.
20v
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【单选题】两个稳压二极管,稳压值分别为 7V 和 9V ,将它们用于图 1.1 所示电路。设输入电压 U 1 值是 20V ,则输出电压 U 0 为( )。 图 1.1
A.
0.7V
B.
7V
C.
9V
D.
20V
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【单选题】两个稳压管,稳压值分别为7V和9V,将它们用于下图电路,设输入电压Ui=20V,则输出电压Uo为( )
A.
0.7V
B.
7V
C.
9V
D.
20V
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【单选题】两个稳压二极管,稳压值分别为 7V 和 9V ,将它们用于下图 mn10.2 电路。设输入电压 U 1 值是 20V ,则输出电压 U 0 为( )。
A.
7V
B.
1V
C.
9V
D.
0V
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【单选题】在数据表中, ( )使用户能够定义一个值,每当用户没有在对应列中输入值时,则系统将自动提供这一列的值。
A.
默认值约束
B.
CHECK 约束
C.
非空值约束
D.
参照完整性约束
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【简答题】听下面一段对话，回答第1-4题。 1. How many people are in the woman's family? A. Three B. Four C. Five 2. What did the children think about having dinner together at home? A. They thought it was funny B. They dislik...
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【简答题】根据对话情景选择恰当的选项,其中有两项是多余的。 A. And we had a very wonderful time. B. How long did you stay there? C. Where did you go last week? D. In two days. E. What is it famous for? F. Did you take a lot of photos? ...
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【单选题】听力原文：W: Your survey sounds very good. How many people filled it in? M: I gave out 120 copies and I got 70 back. W: That's a very high rate of return. Who did you give your questionnaires to? M: I gave...
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His schoolmates.
B.
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【多选题】How did the speaker feel when she first came to the college?
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A.
0.7V
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D.
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【单选题】两个稳压二极管,稳压值分别为7V和9V,将它们用于图 所示电路。设输入电压 U1值是20V,则输出电压 U0为( )。
A.
0.7V
B.
7v
C.
9v
D.
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【单选题】两个稳压二极管,稳压值分别为 7V 和 9V ,将它们用于图 1.1 所示电路。设输入电压 U 1 值是 20V ,则输出电压 U 0 为( )。 图 1.1
A.
0.7V
B.
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C.
9V
D.
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【单选题】两个稳压管,稳压值分别为7V和9V,将它们用于下图电路,设输入电压Ui=20V,则输出电压Uo为( )
A.
0.7V
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C.
9V
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【单选题】两个稳压二极管,稳压值分别为 7V 和 9V ,将它们用于下图 mn10.2 电路。设输入电压 U 1 值是 20V ,则输出电压 U 0 为( )。
A.
7V
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C.
9V
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【单选题】在数据表中, ( )使用户能够定义一个值,每当用户没有在对应列中输入值时,则系统将自动提供这一列的值。
A.
默认值约束
B.
CHECK 约束
C.
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