Jawaban:

A.
1. They write the letter because they want to congratulate Mughbit who had just been accepted into the Department of Economics at the University of Surabaya. They also want to tell him to focus on his study in the university.
2. The senders felt delighted and impressed when they wrote the letter.
3. The sentence means that they reminisced the nights when Mughbit studied so hard that he didn't sleep anymore.
4. The toughest has similar meaning to the hardest.

B.
1. The sentence means that Didi hasn't been eating Elizabeth's father's cooking for so long that she thinks Didi must miss it so much.
2. Didi probably come to the occasion with his siblings.

Penjelasan:

A.

1. We can see that the senders indirectly congratulate Mughbit through the sentences "We must say that we are impressed" and "You've made it.". We can also see that the senders want Mughbit to focus on his study in the university through the sentence"You still have four years of hard work in the future."

2. We can understand the senders' feelings through the sentences "We are delighted to hear..." and "We must say that we are impressed" that they are delighted and impressed when they write the letter.

3. By the sentence "It is one of the toughest program to get into in the country," we know that Mughbit must had been studying hard before to get into the program, and it's proven by the past sentence "Remember those nights without sleep?" that shows how hard Mughbit studiedback then to the point where hedidn't even sleep sometimes.

4. The underlined word toughest has similar meaning to hardest, because toughest means it's the most difficult one to pass, similar to the meaning of hardest.

B.

1. The word miss from the sentence "you must miss my father's cooking" means /rindu/ in Indonesian. We can miss something because we have not done it in a long time. Based on that, we know that the sentence means that Didi hasn't been eating Elizabeth's father's cooking for so long that Elizabeth thinks Didi must miss it so much.

2. Didi will probably come with his siblings because Elizabeth ask him to bring them with him through the sentence "Please bring with you, your siblings, because my sister has prepared special activities and games."

Demikian jawaban saya, semoga bisa dimengerti. Mohon maaf bila ada salah kata. Apabila anda puas dengan jawaban saya, bisa dijadikan jawaban tercerdas. Terimakasih :)