将下列试剂分别加入到氢氧化钠溶液、澄清石灰水和稀硫酸中,能出现三种不同现象的是(

题型:选择题

问题:

将下列试剂分别加入到氢氧化钠溶液、澄清石灰水和稀硫酸中,能出现三种不同现象的是(  )

A.KCl溶液

B.Na2CO3溶液

C.石蕊试液

D.CuCl2溶液

考点:物质的鉴别
题型:选择题

属于不稳定性骨折的是

A.斜形骨折

B.螺旋形骨折

C.粉碎性骨折

D.不完全性骨折

E.横断嵌插骨折

题型:选择题

1937年12月,南京沦陷后,作为国民政府战时陪都的是[ ]

A.武汉   

B.广州 

C.重庆  

D.长春

题型:选择题

依据《电业安全工作规程》的规定,储煤场应有良好的照明、排水沟和消防设备,消防车辆的通路应畅通。

题型:选择题


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.

题型:选择题

()声音格式支持多种压缩,可以具有CD音质。

A.MP3

B.WAV

C.WMA

D.RA\RM

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