I. Fill in the blank in each of the following sentences with a suitable preposition or adverb. 31. They discovered that they could shear sheep, take the wool, weave it and fashion the material ______ warm coats and suits. 32. He laid the groundwork for a good command ______ French at high school. 33. With wisdom we can appreciate life______ the fullest. 34. According to researchers, however, this kind of gossip also has a good side in that it helps us put our own problems ______ perspective . 35. When confronted ______ the evidence of her guilt, she confessed . 36. Grave colors of the picture can reflect despair ______ the painter. 37. Many people believe that they can live on ______ their offspring. 38. A team of nurses assisted the doctor ______ performing the operation. 39. The school board listened quietly as John read the demands that his followers demonstrated ______. 40. The college students in China are kept ______ smoking on campus because this will do them no good.