Could you please tell me which alternatives are possible? Thank you, Writeacher.

1) You usually ....... be at the airport two hours before your flight leaves. (have to; not must or should).
2) At most schools students can go on .... (a trip/on trips) (are both possible?) with the teachers.
3) Sam plays truant (has played truant is a mistake?) a lot so the head teacher has .......(suspended) him from school for two weeks.
4) I..... my History exam (have failed, failed?). I only got 32%. I'm so upset.
5) She first cut her hair short about two years ago. She has had short hair for about two years. She has had her hair cut short for about two years.
6) I didn't pass my Maths exam.
I think you should talk about it to/with your teacher.
7) I think you should talk to your teacher about it.Then you must work hard (not have to work hard??) for your next exams.
You're absolutely right.I must study more.

1) Usually, you should be at the airport two hours before your flight leaves.

2) At most schools students can go on .... (a trip/on trips) (are both possible?) with the teachers.
(Yes, both are possible.)

3) Sam is truant a lot so the head teacher has suspended him from school for two weeks.

4) I failed my history exam. I only got 32%. I'm so upset.

5) She first cut her hair short about two years ago. She has had short hair for about two years. She has had her hair cut short for about two years.
(All are fine.)

6) I didn't pass my maths exam.
I think you should talk about it with your teacher.

7) I think you should talk to your teacher about it. Then you must work hard for your next exams.
You're absolutely right. I must study more.

1) The correct answer is "have to." To determine this, you can eliminate the options "must" and "should" since the question specifies that neither of those is correct. Then, you can choose the correct answer based on the meaning of the sentence. In this case, "have to" is used to express an obligation or requirement, which fits the context of needing to be at the airport two hours before the flight.

2) Both "a trip" and "on trips" are possible. To determine this, you can consider the meaning of the sentence. If the sentence is referring to one specific trip, then "a trip" is appropriate. If it is referring to multiple trips, then "on trips" is preferred.

3) "Has suspended" is correct. This is a grammatically sound sentence. To determine this, you can consider the verb tense and subject agreement. Since the head teacher has already suspended Sam, "has suspended" is the correct verb form.

4) The correct answer is "have failed." To determine this, you need to find the verb form that matches the subject "I" and the past tense. "Have failed" is the correct form for the present perfect tense.

5) Both "has had short hair for about two years" and "has had her hair cut short for about two years" are possible. To determine this, you can consider the meaning of the sentence. If it is referring to the fact that she has maintained short hair for two years, then "has had short hair for about two years" is appropriate. If it is emphasizing that she regularly gets her hair cut short, then "has had her hair cut short for about two years" is preferred.

6) "Talk to your teacher about it" is the correct preposition. To determine this, you can consider the appropriate preposition commonly used after the verb "talk." In this case, "talk to" is the correct preposition.

7) Both "must work hard" and "have to work hard" are possible. To determine this, you can consider the meaning of the sentence. Both phrases express an obligation or necessity to work hard for the next exams.