—____ bag is this?
一It is mine.
只含铜和氧两种元素的固体样品9.0g,测得其中铜元素的质量为8.0g.已知铜的氧化物有CuO和Cu2O两种,下列说法正确的是( )
“夫以铜为镜,可以正衣冠;以史为镜,可以知兴替;以人为镜,可以知得失;”(1)这段话最早是出自谁的名言?(2)“以人为镜,可以明得失”这个 “人”指谁?当时有名的宰相“房谋杜断”分别指哪两个人?
We had a school English speech last week and the winner was a _______ girl from Class 2, Grade 9.