64.　 The hut was dark so it took time for our eyes to __________(适应).

63.　 It was my first visit to a r___________(偏远的) village, a village as far away as you can imagine.

62.　 When I was teaching the boys, I sometimes wondered how _____________(相关的) chemistry is to these students after they left school.

61.　 Dear Rosemary, thanks for your letter, which took a _____________(两个星期) to arrive.