观察植物细胞的质壁分离和复原，选用紫色洋葱作实验材料的效果较好，最主要的原因

阅读判断。   Today we go to the zoo. There are so many animals in the zoo.Look! There are black and white. They are fat. They eat bamboo. Look at the elephant. It's so big. Its nose is so long, and the ears are big. Look at the monkey. It's thin. It lives in the tree. It eats bananas. I love animals. They are so lovely.

如图所示电路，要使灯泡L₁和L₂组成并联电路，应该（　　）

如图所示为某生物核基因表达过程．下列相关叙述不正确的是（　　）

计算．

450÷9×76=____