1knew.hadn't learnt
2left.had already begun
3didn't know.had already arrived
4came.saw.had cooked
5had studied.entered
6was going.looked(здесь Past Continuous,а не Past Perfect)
7had taken.came
8had returned
9got.had already started
10came
11thought.had already returned
12was sure.didn't recognize
13did you find...had lost
14said.had been
15arrived.had already helped
Школа учит нас решать екзамены (тесты), а образование- учит жизни
Везде the, т.к. артикль The ставится у множественного числа или чего-то конкретного. например в этом тексте погода, небо, солнце - единственные в мире. им нельзя ставить артикль a, т.к. а обозначает неопределенность предмета (какой-то). Артикль а ставится ТОЛЬКО у единственного числа.
надеюсь, помогла
Лишнее D потому что начинается на гласную
Dear Dad,
I was so happy to get your letter. I am sorry I haven't answered earlier but I was really busy with my school.
You asked me to tell you about my school. Well, I finished the school year very well. I have to pass many different exams, since I'm in 9th grade. I plan to go to the 10th grade next year. Holidays I will spend with my friends and parents. I think I can come to visit you.
Unfortunately, I'd better go now as I've got a lot of homework to do. Keep in touch!