某同学制氧气时，试管炸裂了，造成试管炸裂的原因可能是下列中的：①没有给试管均匀预热；②夹试管的铁夹夹的过紧；③试管外壁潮湿；④试管口没有向下倾斜；⑤忘了加催化剂；⑥试管没加棉花；⑦收集完氧气先撤酒精灯____ 

A．全部　　 B．①②④C．没有⑤D．没有②③

⑴____What are these?                

⑵____Is there an apple on the table?     

⑶____How many bikes are there ?      

⑷____Can you drive a car?             

⑸____What's the weather like in spring?  

A: There're five.

B: It's warm.

C: They're pears.

D: Yes, there is.

E: No, I can't.