We give away ______ books to the school library last year.
hundred 的用法。
句意：去年，我们捐给学校图书馆六千本书。thousand与具体数字连用时，后面不加-s，不加of；表示概数时，与of连用，词尾要加s，词前不加数字。故选B。
I often have _____ egg and a glass of milk for _____ breakfast everyday.
冠词。
句意：明天早餐，我经常吃一个鸡蛋，喝一杯牛奶。前空egg以元音音素开头，用an，后空考查短语have....for breakfast，意为“早饭吃/喝.....”故选A。