总结 思维导图工具大致可分为三类：网页端、云端、本地。 网页端 → 开源免费，实时编辑，适合轻度用户。推荐 simplemindmap 和 draw（也有本地版）。 云端 → 核心是同步与协作，多数需付费，毕竟有服务器成本。推荐： 飞书：作为附加功能，几乎无付费门槛 幕布：免费版即可满足大部分需求，极. In the United States, 30 became the top-selling album of 2021 [160] within its first day. [161] 30 achieved 2021's biggest opening week, [162] debuting atop the Billboard 200 with 839,000 album-equivalent units, including 692,000 pure album sales. There are 30 days in the months April, June, September and November (and in unusual circumstances February—see February 30). Although the number of days in a month vary, 30 is used to estimate months elapsing. 数学性质 第19個 合數， 正因數 有1、2、3、5、6、10、15和30。 前一個為 28 、下一個為 32。 質因數分解 為 2 × 3 × 5 \displaystyle 2\times 3\times 5 。 第5個 過剩數， 真因數和 為42，盈度為12。 前一個為 24 、下一個為 36。 Properties of 30: prime decomposition, primality test, divisors, arithmetic properties, and conversion in binary, octal, hexadecimal, etc. Share your videos with friends, family, and the world Her first studio album in six years following 25, 30 was inspired by Adele's experiences and anxiety following her divorce and its impact on her son's life, along with motherhood and fame. 1. 论语 中记载孔子三十岁时，因之前十五年的经验，已经满足他在世上 立足 的目的，自称“ 三十而立 ” 。 [1] 2. 阳历 其中4个月有30日 （4、6、9、11月）。 3. 农历 中 大月 的天数 4. Videos and songs from “30” the 2020 Pop Soul album and fourth full-length studio release for British singer-songwriter, Adele.more 30 is the index number for Fibonacci number, F 30 = 832040 = 5∗11∗23∗31∗61 = the largest Fibonacci number with 6 digits. 30 is the smallest integer with three distinct prime divisors.