The Blacks are English . Now they are in Beijing . This is their first visit to China.
   They are going to stay in China for three weeks . They want to learn some Chinese ,too.
   He likes driving in Beijing very much .Mrs Blacks is a teacher .She often visits a middle school in Beijing ,and she likes to speak with students.
They take a lot of photos in China .When they are back to English ,They’re going to show the photos to their friends. They want the English People to know more about China.

计算（2a³）²的结果是（　　）​

“几处早莺争暖树，谁家春燕啄春泥”，这句诗描述鸟的哪种繁殖行为？（　　）

把两种草履虫放在一起培养，它们会争夺食物，其中一种会死亡。这两种生物之间的关系是（    ）