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【简答题】
将冷却水从水池送到高位槽,已知水池比高位槽液面高10m,从水池到泵的吸入 为长10m的89mm×4mm钢管,在吸入管线中有一个90°弯头,一个吸滤阀。泵出口管 直管总长20m的57mm×3.5mm钢管,管线中有3个90°弯头,一个闸阀(全开)和一 全开的截止阀。要求流量20m3/h。贮槽液面维持恒定,贮槽及高位槽液面上大 压。输水管的绝对粗糙度为0.2mm。试求泵所需的理论功率。
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【单选题】We will also see a __________ increase in the number of television per household， as small to displays are added to clocks， coffee markers and smoke detectors.
A.
surpassing
B.
suppressing
C.
startling
D.
stacking
【单选题】下列表达式成立的是
A.
typeof NaN=="number"
B.
isNaN("abc")==NaN
C.
Number("123abc")==parseFloat("123abc")
D.
parseInt(12.5)==parseFloat(12.5)
【单选题】If we see some plants close their leaf pores, we can deduce that they are living in ______.
A.
rainy area
B.
hot area
C.
drought area
D.
windy area
【简答题】We will also see a ________ increase in the number of televisions per household, as small TV displays are added to clocks, coffee makers and smoke detectors. A) startling B) surpassing C) suppressing ...
【单选题】He left home ______a cold morning, and I heard that he was coming back _____ the late afternoon.
A.
in; on
B.
on; on
C.
in; in
D.
on; in
【单选题】I have heard a lot of good things about you __________I came back from abroad.A.since ##
A.
I have heard a lot of good things about you __________I came back from abroad. A.since
B.
until
C.
before
D.
when
【单选题】下列表达式成立的是:
A.
Object obj = new String("hello")
B.
Boolean flag=true;
C.
String s=new StringBuffer();
D.
Number n=new Integer(2);
【单选题】We can see the library between the post office the bank.
A.
but
B.
with
C.
or
D.
and.
【单选题】关于鳃器发生的叙述,哪项错误( )
A.
鳃弓为头部两侧的外胚层增生形成
B.
鳃沟为鳃弓之间的条形凹陷
C.
咽囊为内胚层向外膨出形成
D.
鳃膜是鳃沟与咽囊之间的薄膜
E.
鳃器参与颜面和颈的形成
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