[完型填空]Glasses protect people's eyes from bright light. Microscopes make tiny things larger （ 1 ） we ...

[完型填空]Glasses protect people's eyes from bright light. Microscopes make tiny things larger （ 1 ） we can examine them. Telescopes make objects that are far away appear （ 2 ） closer to us. However in recent years plastics have replaced glass （ 3 ） conditions where glass might be easily broken there are new uses to be developed for glass that were never imagined in the （ 4 ） . Perhaps the greatest （ 5 ） of glass is that its constituent (构成的).parts are inexpensive and can be found all over the world. 4. ____