Returns true if the string contains the given substring.
A notation will be said to be suggestive if the forms of the expressions arising in one set of problems suggest related expressions which find application in other problems.
。新收录的资料是该领域的重要参考
Blue: Associated with Derrick Henry，详情可参考新收录的资料
到了守岁的十二点了，又要放鞭炮，我没再追问宴席的细节。阿爸把那挂红鞭炮提到门口，鲜红的一长串，铺在水泥地上。火星一路蹿过去，红纸炸开，碎屑落满一地。
assert widen([0, 1, 2], Var(2)) == Var(2)