改错：（答案+解析）

51. The train has left for twenty minutes.

52. --How many books had they borrowed?

--Five.But they haven’t finished reading even one.

53. He lost his bike so he has to walk there.

54. --Why did the policeman stop us?

　 --He told us not to drive so fast in this street.

55. The population of the world in 20th century became very much bigger than that in 19th.

56. The magazines are such easy that the children can read them well.

57. –Would you like any more tea?

-Thank you.I’ve had enough.

58. I think basketball is excited.I like to watch it.

59. The math problem is so hard that a little students can work it out.　

60. Though she talks few, she has made a little friends here.

改正+解析

51. The train had been away for twenty minutes.

【解析】for+一段时间表示“长达多久”，当用完成时表示持续动作时，要选择可持续动词，不要用瞬间动词.

52. --How many books did they borrow?

--Five.But they haven’t finished reading even one.

【解析】这里只是问过去发生的一件事，并不是过去时间之前发生的。

53. He has lost his bike so he has to walk there.

【解析】这里大的时间是现在时，前半句用现在完成时，表示丢车对他之后步行的影响，所以用现在完成时。

54. --Why did the policeman stop us?

　 --He told us not to drive so fast in this street.

【解析】 tell sb...not to do sth.... 告诉某人不要做某事。

55. The population of the world in 20th century becam every much larger than that in19th.

【解析】修饰population 通常用large,而不是much或many。

56. The magazines are so easy that the children can read them well.

【解析】easy是形容词，要用so +adj…that..., 而不是such, such+n…that...

57. –Would you like some more tea?

-Thank you.I’ve had much.

【解析】 第一句是虚拟语气，所以some不变。第二句的enough是形容词，不能说had enough。had是动词

58. I think basketball is exciting.I like to watch it.

【解析】 情绪类的形容词有两类，V+ed表示“感到……的”，通常用来形容人(也就是一般是人做主语）；而V+ing表示“令人……的”，通常用来形容物（也就是一般是物作主语）。

59. The math problem is so hard that few students can work it out.　

【解析】 要注意语境，这里指几乎没有什么学生能做出来。 a few,few修饰可数名词，a few虽然少，但强调有，表肯定含义；few少且强调几乎没有，表否定含义；a little与little是修饰不可数名词，其区别同a few与few。

60. Though she talks little,she has made a few friends here.

【解析】要注意语境，这里译文是：虽然她不怎么说话，但她有一些朋友。从句强调否定含义，而主句表肯定。

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