It means a promise ("assurance") which is accompanied by a smile.

there are five or six problems, and it is too hard to answer them all in a list! why not present it as a journal entry for editing. it is too hard to manage this way.

Sufficient Sleep

I can't say I sleep enough, because sometimes I sleep a lot, sometimes I sleep a little. It depends on many different factors. But, as is true for many other people, I know more or less (note:  "about" could have a different meaning here) how much sleep is sufficient for me. If I sleep about 8 hours and I sleep well and deeply, then the next day I feel good. Seven (don't start a sentence with a number) hours is also enough for me, but when I sleep like this I know that the closer the evening comes, the less vigorous I will be. The worst thing happens when I divide my night sleep into parts:  Sometimes I wake up in the middle of the night or closer to the early morning and feel good. It seems to me then that I have slept enough to start working or doing something. I begin to learn English or read books etc. It's a tricky thing, because I know that this is an illusion; my drowsiness will come back. And indeed, soon my enthusiasm drops to zero. I yawn terribly and fall into bed. Make a guess what time I usually wake up then!
I suppose I ought to try to change these habits, especially knowing that I always dream about early morning as the time for doing  good things such as reading or learning languages. One needs to make just a little effort: to go to bed on time in the evening and sleep. But the easiest things are usually hardest. So it goes.

Help(please)

Hi, there

In the sentence "it was confirmed that Saudi Arabia — officially the weakest of all the teams who had to qualify for next year’s World Cup, according to FIFA’s rankings(...)" What does "had to qualify" mean? And why "rankingS", if there is only one?

Please

answer:

"had to qualify" means "were required to qualify"  

And when they speak of "FIFA's rankings" they are speaking of FIFA's list of the rankings of all countries.

So read it like this:  "It was confirmed that Saudi Arabia (which according to the FIFA rankings of all countries was officially the weakest among all the teams that were required to qualify for next year's World Cup) [the rest of the sentence that you didn't put in here.]." 

i hope this helps.....

PLEASE CORRECT MY GRAMMAR

Today I woke up at 1 a.m. because of a power failure. I went to sleep again when the lights went on, at around 2 a.m.. and then I woke up again at 5 in the morning. As always, I practiced the guitar for about 30 minutes. After that, I took a shower and at 6:00 met my student on Italki from the US.

My weekend

this weekend was good!
Saturday morning I went shopping and in the afternoon I cleaned the house.
Sunday morning I stayed at home and decorated the Christmas tree.  Then in the afternoon I went shopping in a store.
Sunday morning we had a very good panettone. Usually I don't eat a lot of sweets but I like panettone very much, especially because with its long rise it is very digestible.
Sunday for lunch we bought some pizzas but I didn't like them because they were overcooked.