In the past, importance was not given to shoes being comfortable or fashionable. These early foot coverings were probably animal skins, which people tied round their ankles during cold (1)______. We still use leather today, but other materials such as silk, plastic, or cotton are also popular, depending (2) ______ what is in fashion. It was only one hundred and fifty years ago that people began to wear a different shoe on each foot. Formerly, the two shoes had been straight instead of shaped and (3) ______ be worn on the left or the right foot. All shoes used to be made by hand, but now, (4) ______ there are shoemakers still using their traditional skills, most shoes are now machine-made in large factories. The introduction of sewing machines allowed the shoe industry to produce a large (5) ______ of cheaper shoes for a wider range of buyers. 36. A. weather B. climate C. temperature D. condition 37. A. in B. of C. from D. on 38. A. had to B. could C. ought to D. should 39. A. although B. if C. unless D. since 40. A. number B. total C. sum D. size