engraved block, photo-typegraphy, process block

exploration,photography etc,thus giving a free space to aerospace photography reconnaissancc satellites which have been developing rapidly and successfully.

现代国际公约规定,一国的领空限制在80—110千米以下,在此以上像公海一样属于公空,可以自由飞行,因此容许别国飞行物,包括人造卫星,进行各种正常活动,如:探测,照相等等。

This article summarizes the methods of and the author s views on how to use the tech- nique of vertical reflective photography in the teaching of experiments.

利用定向反射镜进行垂直定向反射照相，是近年来出现的照相新技术。