a strange question

[Unregistered Lina]

Hello

I happened to find the question which I think is strange.

Would you look at this? I should choose the words in the parenthesis.

#1 Children (are sleeping / sleep / will be sleeping ) by the time I get home.

I think there is not appropriate answer in the parenthesis because of " by the time I get home." Is that right?

If I use "will be sleeping", what should I change this part? Is #2 or #3 OK?
If it's not, would you give me some sentence that make sense?

#2 Children will be sleeping at the time I will get home.
#3 Children will be sleeping at the time I get home.

Thank you.

[Casiopea]

Hello

I happened to find the question which I think is strange.

Would you look at this? I should choose the words in the parenthesis.

#1 Children (are sleeping / sleep / will be sleeping ) by the time I get home.

I think there is not appropriate answer in the parenthesis because of " by the time I get home." Is that right?

If I use "will be sleeping", what should I change this part? Is #2 or #3 OK?
If it's not, would you give me some sentence that make sense?

#2 Children will be sleeping at the time I will get home.
#3 Children will be sleeping at the time I get home.

Thank you.

Our sentence is referring to the future. You haven't gotten home yet, but when you do get home, the children will be sleeping:

By the time you get home, the children will be sleeping.
When you get home, the children will be sleeping.

The children will be sleeping by the time you get home.
The children will be sleeping when you get home.