考虑到沙漠地区特殊的地理条件，沙漠公路路面材料的设计和应用要遵循适用性、可行性和经济性的原则。
Because of the special geographical condition of the desert area, the pavement material design and application for desert highway must comply with the principle of utility, feasibility and economy.
EASA预计，更简单的条件将使得更多的制造商制造更加经济的飞机，而且无需放弃高安全标准的可行性更高。
EASA expects that the simplified conditions will make it possible for more manufacturers to build economical aircraft without giving up the high safety standard.
根据黑岱沟露天煤矿的条件，研究了黄土剥离采用半连续工艺的可行性及方式。
According to the conditions of the surface coal mine in Heidaigou, the semi-continuous mining system for loess stripping was put forward, and the feasibility of this system was studied.
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