Comprehensive 'Let's Read 1' worksheet designed to help young learners practice phonics, identify word families, and construct simple sentences.

Let’s go step by step to solve the fill-in-the-blank part at the bottom right of the page.

We are given:

> It __ a doll.
> It __ a frog.
> It __ a box.

And above that, we have examples like:

> It is not a doll.
> It is not a frog.
> It is not a box.
> It is not a clock.

Also, earlier in the worksheet, we see sentences like:

> It is a dog.
> It is a frog.
> It is a fox.
> It is a cock.

So the pattern is:
- When something is that object → use “It is a ___.”
- When something is not that object → use “It is not a ___.”

Now look at the pictures next to each blank (even though I can’t describe them, based on standard worksheets like this):

The first line says: “It __ a doll.” — and there’s likely a picture of something that is NOT a doll (maybe a frog or box). But wait — let’s check the context from the rest of the page.

Actually, looking at the section just above the blanks:

There’s a box with:

> It is a sock. It is a doll.
> It is a cock. It is a dog.
> It is a clock. It is a box.

Then below that:

> It is not a doll.
> It is not a frog.
> It is not a box.
> It is not a clock.

This suggests that for the final exercise, we’re being asked to complete sentences where the subject does NOT match the noun — so we should use “is not”.

But wait — let’s look again at the exact layout.

In the bottom-right corner, it says:

> It __ a doll.
> It __ a frog.
> It __ a box.

And beside each line, there is probably an image showing what “it” actually is. Since this is a common phonics/reading worksheet, and based on typical patterns:

Usually, in such exercises, if the picture shows a frog, then:

→ “It is a frog.” would be correct for that one.

But here, the three lines are grouped together under the same heading as the “not” examples.

Wait — let me re-express logically.

Look at the very last block before the blanks:

It says:

> It is not a doll.
> It is not a frog.
> It is not a box.
> It is not a clock.

That’s teaching the negative form.

Then immediately after, we have:

> It __ a doll.
> It __ a frog.
> It __ a box.

With no pictures shown in text, but since this is a follow-up to the “not” examples, and because the previous sentence was “It is not a...”, it’s likely that these blanks are meant to be filled with “is not” — unless the picture contradicts.

BUT — hold on! Let’s think about the flow.

Earlier in the worksheet, students learn:

Positive: “It is a ___.”
Negative: “It is not a ___.”

Then they practice matching words to pictures.

In the bottom section, the three lines are probably paired with images that show things that are NOT those objects — hence requiring “is not”.

However, without seeing the actual images, we must rely on standard design.

Actually — let’s look at the structure again.

Right above the blanks, there’s a box that lists:

“It is a sock. It is a doll.
It is a cock. It is a dog.
It is a clock. It is a box.”

Then below that, another box says:

“It is not a doll.
It is not a frog.
It is not a box.
It is not a clock.”

Then comes the exercise:

“It __ a doll.
It __ a frog.
It __ a box.”

Given that the immediately preceding example uses “is not” for doll, frog, box — it’s highly likely that the intended answer for all three blanks is “is not”.

Moreover, in many such worksheets, this section tests whether the student can apply the negative form correctly when the picture doesn’t match the word.

Therefore, assuming the pictures next to each blank do NOT show a doll, frog, or box respectively (which is standard for this type of drill), we fill in “is not”.

Final verification:

If the picture next to “It __ a doll.” is, say, a frog → then “It is not a doll.” ✔️
If the picture next to “It __ a frog.” is, say, a box → then “It is not a frog.” ✔️
If the picture next to “It __ a box.” is, say, a doll → then “It is not a box.” ✔️

Yes — this makes sense pedagogically.

So the answers are:

It is not a doll.
It is not a frog.
It is not a box.

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Final Answer:
is not
is not
is not