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【单选题】
Suppose country A, a labor-abundant country, produces only wheat and cloth. The following equations illustrate the prices and costs of wheat and cloth in the country , where the numbers indicate the amounts of labor and land needed to produce a unit of wheat and cloth. ‘ w ’ is the wage rate and ‘ r ’ is the rental rate of land . Price of wheat = 1w + 2r Price of cloth = 2w + 1r Suppose country A engages in free trade and the price of cloth increases from $3 per unit to $4 per unit. T he price of wheat remains unchanged at $3 per unit . T he wage rate and the rental rate change to _____ and _____ respectively. _____ . a. $ 3/8; $ 7/8 b. $1; $5/3 c. $ 5/3; $ 2/3 d. $ 4/7; $ 3/7A.
B.
C.
D.
D
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【单选题】After the class was over, the student apologized ___ the teacher ____ his coming late.
A.
for; to
B.
to; with
C.
with; to
D.
to; for
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A.
are needed
B.
need
C.
is needed
D.
needs
【简答题】下图某工程三级抗震,请计算图中现浇板的钢筋工程量。板环境类别 一 类,砼 C25, L AE =36d,L L =48d,板的保护层厚度为15 mm ,梁的保护层厚度为 25 mm , 柱子均为 KZ1:400 mm *400 mm , 四根梁均为 KL1 ,截面尺寸为 300 mm *500 mm ,图纸所标注负筋尺寸未包括锚入梁内的长度. 钢筋名称 方向 钢筋规格 计算式(单位: mm ) 板...
【单选题】After the class was over, the student apologized _______ the teacher ______ his coming late.
A.
/; because
B.
/; for
C.
to; because
D.
to; for
【简答题】（14分）布洛芬、非诺洛芬、酮洛芬是一类芳基丙酸类非甾体抗炎药，具有抗炎作用强、毒副作用低的药效特点。 其中酮洛芬可由芳香族含氧衍生物A经以下路线合成得到： 请根据合成酮洛芬的路线回答下列问题。 (1)已知有机物A可以与NaHCO 3 反应，则A的结构简式为 。 (2)上述合成酮洛芬的路线有5步反应，其中属于取代反应的共有几步？ 。其中有一步反应中用到有机物 ，请写出实验室保存该有机物方法： ...
【单选题】Instructions for homework have to be ____ so that every student knows clearly what is to do after class. [ ]
A.
specific
B.
generous
C.
general
D.
detail
【单选题】“No student,”the headteacher stressed, “_______ go out of the school after ten o’clock at night without my permission. ”
A.
shall
B.
will
C.
must
D.
may
【单选题】如图所示，现浇板，保护层厚度取20mm，图中未注明的梁宽为300mm，轴线居中，分布筋间距为φ8@250，温度筋为φ8@200，②轴线上支座负筋的下料长度为（）。（90°弯曲调整值扣除2d）【图片】
A.
2160
B.
2200
C.
2128
D.
2144
【单选题】如图所示，现浇板，保护层厚度取20mm，图中未注明的梁宽为300mm，轴线居中，分布筋间距为φ8@250，温度筋为φ8@200，图中②轴线②支座负筋内侧布置的分布筋长度为（）。（图中支座负筋伸入板内的长度从梁中线起算）【图片】
A.
4000
B.
4150
C.
4300
D.
4000+2LlE
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