在组装件吊装完毕后，可以在高空将拆除的卸扣往下抛掉。

实验室用粗锌与稀硫酸反应制取氢气，利用氢气还原氧化铜来测定铜的相对原子质量。实验装置如下：

（1）在启普发生器中纯锌与稀硫酸反应过于缓慢，可采取的加快速率的措施是①适当增大硫酸的浓度，②_______________________。

（2）用纯度不高的锌(粗锌)制取氢气，反应速率快，但制得的氢气因含H₂S等还原性杂质而有难闻的气味，CuSO₄洗气瓶中观察到的现象是_______________，是否可以将CuSO₄溶液换成浓硫酸_________(答“是”或“否”) ；理由是__________________________。

（3）有同学发现粗锌与稀硫酸反应一段时间后，锌粒表面变黑，于是收集了少量该黑色固体，验证黑色固体含铁元素的简单化学方法_________________________________________。

（4）实验中得到的数据有：小瓷皿的质量mg，小瓷皿加样品的质量n g，反应后小瓷皿加固体的质量w g，已知氧的相对原子质量为16，则铜的相对原子质量是____________(用含m、n、w的代数式表示)。

（5）某次实验中测定结果明显偏大，可能的原因是________(选填编号)。

a．未充分冷却即停止通氢气        b．氧化铜样品中含有氯化铵杂质

c．反应后固体中有少量Cu₂O        d．氢气不干燥有少量水分

（6）由于启普发生器药品用量较多，利用下列仪器装配一套有启普发生器功能的简易装置，你选择____________(选填编号) (支撑仪器、橡皮塞、导气管略)。

(a)     (b)      (c)      (d)      (e)       (f)

2000年5月8日甲作为出租人与乙订立租赁合同，约定将甲的房屋于同年7月1日租赁给乙作为办事处。同年6月10日，甲向丙购买该出租房屋，并办理了产权转让手续。甲与乙于5月 8日所签租赁合同因甲对该房屋尚无处分权而无效。 ( )

筛选

下列关于注射剂质量要求的论述，错误的是（）

A.溶液型注射剂应澄明

B.静脉输液应尽可能与血液等渗

C.用于配制注射液前的半成品，不需要检查重金属和有害元素，在成品中检查

D.乳浊液型注射剂不能用于椎管注射

E.静脉推注用乳液型注射液分散相球粒的粒度不得大于5μm

Throughout history has (1) changed his physical environment in order to improve his (2) of life. With the tools of technology he has (3) many physical features of the earth. He has (4) woodlands and prairies into farms and made lakes and reservoirs (5) of rivers for irrigation purposes or hydroelectric (6) . Man has also modified the face of the earth by (7) marshes and cutting through mountains to (8) roads and railways.
However, man’s (9) to the physical environment have not always had beneficial results. Today, (10) of the air and water is an increasing danger to the health of the (11) . Each day thousands of tons of gases come out of the exhausts of motor vehicles. (12) from factories pollutes the air of industrialized areas and the surrounding (13) of the countryside. The pollution of water is equally harmful. The whole ecological (14) of the sea is being changed and (15) wastes have already made many rivers lifeless.
Now (16) protection is more pressing than ever before. As we know, massive destruction of the environment has brought about (17) effects and even poses a great (18) to man’s existence. Indifference to these problems will mean committing suicide. Therefore, effective (19) should be taken and laws passed to (20) the environment. Otherwise, man is certain to suffer from the serious consequences caused by this lack of care for his living surroundings.