There were masses of dark clouds in the sky.
天上有朵朵乌云.
It is during these seasons that the differences in temperature between warm and cold masses of air are greatest.
就在这些季节里,热气团与冷气团的温差最大。
The hunger, cold and misery then pervading Russia had reached the point of exasperating the masses and making them ripe for revolution.
当时饥饿、寒冷、苦难笼罩着俄国,这些使得民众激愤,革命的时机成熟了。