创建一个尺寸为200px乘200px的GIF，内含由单词‘abracadabra’构成的倒三角形。GIF应为白色背景和黑色字母。每一行从顶部开始为完整的单词'abracadabra'，然后每行末尾依次去掉一个字母，直到只剩一个字母。确保每行前后各有一个空格。这些行应以动画方式依次出现。

create a gif width 200px and height 200px of an inverted triangle shape from the word abracadabra, the top row is the full word, the lower is the last letter less, continue rows till 1 letter is left, white background, black letters, appearing one after another,  each row begins with a space and finishes with a space

Q: What dimensions should the GIF have?
A: For example, width 200px and height 200px.

Q: What background color do you prefer for the GIF?
A: For example, transparent or white.