《我的思念是圆的》中三首咏月诗的不同之处( )
A:时代不同
B:形式不同
C:所咏之月不是八月十五
D:内容不同
--- Where is Jim? --- He _________ to the museum. He hasn't come back.
如图,给试管里的水加热,水沸腾后,水蒸气推动橡皮塞冲程试管口,这个过程与四冲程汽油机的哪一个冲程中的能量转化是相同的( )
— Wonderful! I think it is ______ a meaningful TV show that ______ many people like watching it.
1859年达尔文发表巨著《物种起源》,提出了以____ 学说为核心的生物进化理论.
7x=17.5
x=____