Only one streetlamp in the village is displayed

While trying out the Babylon.js introduction sample, I noticed that only one streetlamp was being displayed.

https://playground.babylonjs.com/#KBS9I5#94

The error details are as follows.

index.js:21 Uncaught (in promise) ReferenceError: lamp3 is not defined

The cause is likely that the Babylon.js Playground has switched to strict mode.

The following shows the results of the sample corrections.

https://playground.babylonjs.com/#KBS9I5#39688

I have submitted the corrected code.

approved! thanks a lot :slight_smile: