Conspires

Directions: Some words in the passage below have been highlighted. Select the best meaning for the corresponding word.

These two factors, the altitude and the weather, tend separately and together to defeat the climber. The height weakness slows him down; it forces him to­ spend days and nights in the course of his assault on the summit. The weather, besides adding to the ­demands of his energy and moral fortitude, conspires to deny him the time he needs to complete his mission. Whereas in lower mountains and on easy ground the weather may be no more than a handicap, in the high Himalayas it is decisive, regardless of terrain. The deduction to be drawn from these two factors was clear enough. We must either so fortify ourselves , that we could continue, without detriment, to live and have our being above the limit of natural acclimatization, better still, we must solve the problem of speed. It was desirable, in fact, that we should meet both these requirements and thus give to those chosen to attempt the summit, some measure of insurance against ­the vagaries of the weather.