`63`. For two months now the police has looked for him.

`->` S + started + Ving + thời gian + ago = For + khoảng thời gian + S + has/have + Vpp

`64`. This is the first time I have (ever) seen a dirtier-looking dog.

`->` This is the first time + S + have/has + Vpp

`65`. It is hours since Mary last rang.

`->` It is + thời gian + since + S + (last) + V2/ed

`66`. Alan hasn't visited his parents for ages.

`->` It is + thời gian since + S + (last) + V2/ed = S + have/has + not + Vpp + for + thời gian

`67`. It is over six months since John (last) had his hair cut.

`->` It is + thời gian since + S + (last) + V2/ed = S + have/has + not + Vpp + for + thời gian

63. For two months now the police has looked for him

64. This is the first time i have seen a dirtier - looking dog 

65. It is hours ago since Mary rang

66. Alan hasn't visited his parents for ages

67. It is over six months since John had his hair cut