31. I cant¹ tell the twins apart.                             

我辨认不出这对双胞胎。

32. A truck appeared over the hill.                      

一辆卡车在山丘上出现。

33. The journal makes its appearance once two months.     

这本刊物两个月出版一次。

34. We should not judge a person by his appearance.         

我们不应该以貌取人。

35. An apple is a kind of fruit.                          

苹果是一种水果。

36. This rule cannot be applied² to every case.    

这项规则不是所有情况都使用。

37. In this way they can better apply theory to practice

这样他们就能更好地把理论运用到实践中去

38. You can join the class if you parents approve.           

如果你父母同意，你可以参加这个班。

39. The city council approved the building plan.　          

市议会批准了这项建筑计划。

40. The equipment must be bought from a supplier approved by the company.

设备必须从公司认可的供应商那里购买。

41. He moved into this house in April.               

他是四月份搬进这所房子的。

42. His left arm was hurt in an accident.             

他的左胳膊在一次事故中受伤了。

43. Justice has long arms.                                  

天网恢恢，疏而不漏。

44. They were not allowed to use arms.              

不许他们使用武器。

45. The new battleship shall be armed with 16-inch guns .

新战舰将以16英寸口径的大炮武装起来。

46. He joined the army a year ago.                       

一年以前，他参军了。

47. The increasing army of the unemployed³ has attracted the attention of the economist⁴.

 不断增长的失业大军引起了这名经济学家的关注。

48. He looked around but could see nobody.               

他四处望了一下，看不到什么人。

49. He turned around as he heard a noise behind him.   

他听到身后有响声，便转过身来。

50. I will visit you around Christmas.                            

我将在圣诞节前后去拜访你。