在迪拜,鸽子屎袭击行人和腐蚀迪拜塔而成了大麻烦;在盛产羊皮具的摩洛哥,鸽子屎因能够去除羊皮中的腥味而成为香悖悖。这表明
The development of industry has been ____gradual process throughout _____ human existence, from stone tools to modern technology.
The police are trying to find out the ____ of the woman killed in the traffic accident.
---I got a rise in salary! ---_____________.
He went home for lunch____ the clock struck twelve.
I would rather ________ to work after my graduation, but my father would rather I ________ abroad for further education.