— Where is John?
— He _____ in the library. He often _____ there in the afternoon.
根据本题语境可知，他现在正在图书馆里看书，他经常下午去那里。答语的第一句用了现在进行时，结构为 is reading；根据 often 可知，答语的第二句用了一般现在时。故答案为选项B。
Do you enjoy _____ about different places in the world?
本题考查 enjoy doing sth. 的固定搭配。该短语意为“喜欢做某事”，故所缺的词是 learning。