Vt lại câu theo câu dk 

73. The teacher was very angry. His pupils did their homework carelessly

……………………………………………

74.He doesn’t eat fish when he isn’t extremely hungry.

If……………………………………………

75. We didn’t hurry, so we were late for the concert.

If……………………………………………

76. In order to get a driver’s license, you must be at least 18 years old.

If you……………………………………………

77. A person must have a passport to be able to travel abroad.

A person cannot travel abroad unless_………………………………

78. Ann’s having a lot of trouble because she lost her passport last week.

If……………………………………………

79. Tom doesn’t do anything if you don’t tell him what to do.

Unless …………………

80. We must take steps to preserve natural resources, or the planet will be in danger.

Unless………………………………………

81. It’s such a pity your sister can’t come as well.

If only……………………………………………

Answer:  
73. If the pupils had done their homework carefully, the teacher wouldn't be angry.
74. If he isn't extremely hungry, he doesn't eat fish.
75. If we had hurried, we wouldn't have been late for the concert.
76. If you are not at least 18 years old, you cannot get a driver's license.
77. A person cannot travel abroad unless they have a passport.
78. If Ann hadn't lost her passport last week, she wouldn't be having a lot of trouble.
79. Unless you tell him what to do, Tom doesn't do anything.
80. Unless we take steps to preserve natural resources, the planet will be in danger.
81. If only your sister could come as well. 

Câu điều kiện loại 1:

If + S +  V(s/es) + O, S +  will/can/... +  V_inf + O

Câu điều kiện loại 2:

If + S + V-ed, S  + would/could/...+ V-inf + O

Câu điều kiện loại 3:

If + S + had + Vpp/V-ed, S  + would/could/... + have + Vpp/V-ed + O

Unless `\ne` If

`73`.  If the teacher hadn't done their homework carelessly , his pupils would not have been very angry.

`74`. If he were extremely hungry , he would eat fish.

`75`. If we had hurried, we wouldn't have been late for the concert

`76`. If you want to get a driver's license, you must be at least `18` years old.

`77`. A person cannot travel abroad unless she has a passport.

`78`. If Ann hadn't lost her passport last week, she wouldn't be having a lot of trouble.

`79`. Unless you tell him what to do, Tom won't do anything.

`80`. Unless we take steps to preserve natural resources, the planet would be in danger.

`81`. If only your sister could come as well.

`-` ĐK loại 1: If + S + V(htđ), S + will + V-inf

`-` ĐK loại 2: If + S + V2/ed (were), S + will + V-inf

`-` ĐK loại 3: If + S + had + V3/ed, S + would + have + V3/ed

`-` If only + S + V2/ed ~ quá khứ