山西省2012
高考英语二轮复习专题训练：完型填空（60）阅读下面短文，从短文后各题所给的四个选项（a、b、c和d）中，选出可以填入空白处的最佳选项。 at the beginning of this century, medical scientists made an interesting discovery; we are built not just of flesh（肌肉）and blood but also of time. they were 1 to show that we all have a “body clock” 2 us, which controls the 3 and fall of our body energies, 4 us different from one day to the next. the 5 of a “body clock” should not be too 6 since the lives of most living things are controlled 7 the 24 -hour night-and-day cycle（循环）. we feel 8 and fall asleep at night and become 9 and energetic during the day. if the
