A:x1=﹣1,x2=﹣3.5
B:x1=1,x2=﹣3.5
C:x1=1,x2=3.5
D:x1=﹣1,x2=3.5
Not having __________ her daughter abroad for a long time, the mother was very worried.
一____战舰 一____坐骑 一____书籍 一____诗扉 一____感情
“观察DNA和RNA在细胞中的分布”实验中,正确的操作步骤是①染色 ②水解 ③冲洗涂片 ④取口腔上皮细胞制片 ⑤观察