Complete the advice about booking a holiday with the correct comparative or superlative form of the
adjectives.
3
Booking a holiday?
Price isn't everything when you're booking a holiday,
and the
(cheap) holiday
isn't necessarily the 2
(good
one. For example, one hotel may cost less than another,
but it may be a long way from the airport, so it's
(expensive) to get
there by taxi. Also, a hotel that has low prices might
have a 4
(small
) pool than
other hotels. This probably means the pool will be
(crowded) and not much fun!
Many people choose the 6
(big) hotel they can find because they think this will have
the 7
(comfortable)
rooms. But this isn't always true, and big hotels are often
(noisy) than small ones.
So, when you're looking for a holiday, don't just think
about price - think about which holiday will be the
(enjoyable) for you
5​

All countries have conventional but important behaviour rules that could be explained by inhabitants only. So, you've come to Russia but you haven't know about these rules yet. I'll help you learn primary of them. 
Firstly,russuians usually cede pleces to aged people in the bus. We take care about our elderly. This rule should be known to you,for sure. 
Secondly,russians usualy take off their footwear before entering the house. Perhaps,it could seems rather strange. But this is russian behaviour rule.
Thirdly, we usualy say "enjoy your meals" to each other before dinner,supper. It's not typical for your country,isn't it? Also,when russians have a meet they can kiss each other. We don't open gifts out of hand,which was presented to us. There are many another rules. But, we have to remember foreigners don't aware about all our rules and as long as you staying friendly and polite don't worry about your a little bit strange behaviour.  
Вот исправленный вариант.

1.Nick is the happiest boy that I know. – Ник – самый счастливый мальчик, которого я знаю.

2.Of the six cars, I like the silver one best. – Из шести машин мне нравится серебристая больше всего.

3.Jane’s notebook is cheaper than mine. – Ноутбук Джейн дешевле, чем мой.

4.This is the most delicious cheese-cake I have ever had! – Это самый вкусный чизкейк, который я пробовала!

5.This bookcase is more beautiful than that one. – Этот книжный шкаф красивее, чем тот.

6.Do you feel better today than yesterday? – Ты чувствуешь себя лучше сегодня, чем вчера?

7.I think my cat is the prettiest of all the cats in the world. – Думаю, что моя кошка – самая красивая кошка в мире.

8.Steve Jobs is more famous than Stephen Wozniak. – Стив Джобс более известен, чем Стивен Возняк.

9.This week the weather is hotter than last week. – На этой неделе погода жарче, чем на неделе.

10.Our new house is more expensive than the old one. – Наш новый дом дороже, чем старый.

11.Girls are usually cleaner than boys. – Девочки обычно более чистые, чем мальчики.

12.Chemistry was the hardest subject at school. – Химия была самым трудным предметом в школе.