被誉为“光纤之父”的华人科学家高锟荣获2009年诺贝尔化学奖。下列叙述错误的是(         )

A．SiO₂是生产光导纤维的主要原料

B．SiO₂与CO₂（干冰）的晶体结构不同

C．干冰和SiO₂固体熔化时破坏的作用力是相同的

D．二氧化硅晶体中不存在SiO₂分子，因为它含有类似金刚石的空间网状结构

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.