下列多项式应提取公因式5a2b的是( )
A:15a2b-20a2b2
B:30a2b3-15ab4-10a3b2
C:10a2b-20a2b3+50a4
D:5a2b4-10a3b3+15a4b2
按要求完成句子。
夸父遗憾地看着西沉的太阳。
缩句
看图,读一读,选择正确的句子。
A. Hello. This is my mother. I loveher.
B. Hello. I'm Grandma and this is yourGrandpa.
C. Look, this is my classmate. His nameis Bob.
D. Good morning, Kitty.
①顺应潮流、平等互利 ②睦邻友好、合作共赢
③迎接挑战、呼唤和平 ④求同存异、政冷经热