Copyright

We have marked references of images. 

For images with reference " Photo by A.A. on Unsplash", they are from a coyright-free website which allows the pubilc to use images from the website for commercial or noncommercial purpose. The website is called Unsplash, and the website address is https://unsplash.com/

For images with "Photo from wix.com", we got them from WIX.