色多多在线观看播放-色多多在线观看高清免费-色多多在线观看视频-色多多在线看-欧美aaaaa性bbbbb小妇-欧美aaaav免费大片

If you can't explain your chemistry to a non-scientist, you don't understand it well enough.

We don't inherit the oceans from our ancestors; we borrow them from our children.

在所有時代，困擾人類并給他們帶來最大災難的大問題，不是世界上是否有權力，也不是權力從何而來，而是誰應該擁有它。