73．为啥不写封感谢信呢?(note )

72．李华对集邮很感兴趣。(collect)

71．谢谢你照看我的小狗。(look after)

55．Of all the________ (季节)，I think spring is the best．

54．Nothing is________(不可能的)．

53．Would you mind ________ (吸烟)here?

52．My parents don’t________ (允许)me to stay outside on school nights．

51．There are at________ (至少)thirty birds in the tree．