diff --git a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-a-tooltip-to-a-d3-element.english.md b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-a-tooltip-to-a-d3-element.english.md
index bb42ec996d..efb0058b07 100644
--- a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-a-tooltip-to-a-d3-element.english.md
+++ b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-a-tooltip-to-a-d3-element.english.md
@@ -106,8 +106,49 @@ tests:
## Solution
-```js
-// solution required
+```html
+
+
+
+
+
```
diff --git a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-attributes-to-the-circle-elements.english.md b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-attributes-to-the-circle-elements.english.md
index 1b2382f65c..71d3fc8dc2 100644
--- a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-attributes-to-the-circle-elements.english.md
+++ b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-attributes-to-the-circle-elements.english.md
@@ -103,8 +103,42 @@ tests:
## Solution
-```js
-// solution required
+```html
+
+
+
+
```
diff --git a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-axes-to-a-visualization.english.md b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-axes-to-a-visualization.english.md
index fa0dbf93b1..9518ead02c 100644
--- a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-axes-to-a-visualization.english.md
+++ b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-axes-to-a-visualization.english.md
@@ -130,8 +130,71 @@ tests:
## Solution
-```js
-// solution required
+```html
+
+
+
+
```
diff --git a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-document-elements-with-d3.english.md b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-document-elements-with-d3.english.md
index 6fcc08e8b3..105dac465d 100644
--- a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-document-elements-with-d3.english.md
+++ b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-document-elements-with-d3.english.md
@@ -78,8 +78,14 @@ tests:
## Solution
-```js
-// solution required
+```html
+
+
+
```
diff --git a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-inline-styling-to-elements.english.md b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-inline-styling-to-elements.english.md
index cdb93dc2c6..f6a765501b 100644
--- a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-inline-styling-to-elements.english.md
+++ b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-inline-styling-to-elements.english.md
@@ -64,8 +64,21 @@ tests:
## Solution
-```js
-// solution required
+```html
+
+
+
+
```
diff --git a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-labels-to-scatter-plot-circles.english.md b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-labels-to-scatter-plot-circles.english.md
index 4ad5fa8039..23c46728ad 100644
--- a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-labels-to-scatter-plot-circles.english.md
+++ b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-labels-to-scatter-plot-circles.english.md
@@ -109,8 +109,50 @@ tests:
## Solution
-```js
-// solution required
+```html
+
+
+
+
```
diff --git a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-styles-based-on-data.english.md b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-styles-based-on-data.english.md
index b38b362377..f7e13ef2e0 100644
--- a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-styles-based-on-data.english.md
+++ b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-styles-based-on-data.english.md
@@ -86,8 +86,20 @@ tests:
## Solution
-```js
-// solution required
+```html
+
+
+
+
```
diff --git a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-the-color-of-an-svg-element.english.md b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-the-color-of-an-svg-element.english.md
index fd62ef5a8e..3fb3faee79 100644
--- a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-the-color-of-an-svg-element.english.md
+++ b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-the-color-of-an-svg-element.english.md
@@ -72,8 +72,32 @@ tests:
## Solution
-```js
-// solution required
+```html
+
+
+
+
```
diff --git a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-the-presentation-of-a-bar-chart.english.md b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-the-presentation-of-a-bar-chart.english.md
index e773411c16..5ac09a4132 100644
--- a/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-the-presentation-of-a-bar-chart.english.md
+++ b/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/change-the-presentation-of-a-bar-chart.english.md
@@ -106,13 +106,10 @@ tests:
.enter()
.append("div")
.attr("class", "bar")
- // Add your code below this line
- .style("height", (d) => (d*10 + "px"))
-
-
- // Add your code above this line
+ .style("height", (d) => (d * 10 + "px"))