问题详情：
每句有一处错误，请按以下要求改错：
错误：把某词改为某词。写为：某词---某词。例如: was--were
增加：在某词后加某词。写为：某词后加某词。例如：by后加the
删除：去掉多余的词。写为：去掉某词。例如：去掉a
39. Comparing with 2005, the price of grain was increased by 50%.
40. Rather than driving himself, he always prefers to ride a bicycle.
41. It will depend on if this problem can be solved.
42. I have some doubt that they can complete the task on time.
43. This teacher often helped me maybe because he felt itself his duty to do so.
44. Some of the tall trees were measured over 90 metres.
45. It’s very late to take any buses, so we have to walk home.
46. As long as I know, they live in the same neighbourhood.
47. The organization is in charge of David who is very capable of managing it.
48. We took turn to drive when going to the seaside.
【回答】
39. Comparing-Compared 40. driving-drive 41. if-whether 42. that-whether
43. itself-it 44. 去掉were 45. very--too 46. long-far 47. in 后加the 48. turn-turns
知识点：其他
题型：短文改错
