各单位保存的会计档案一般不得借出，如有特殊需要，经单位负责人批准后可以借出。
参考答案：对
补全对话。
A: Hi, Li Lei, come and 1._____ soccer with me.
B: Sorry, I can't.I 2_____ 3_____ do some washing first.
A: Oh, do you have to?You 4_____ do it after supper.
B: Well, I'm afraid not.Yesterday my mother asked me to 5_____ my clothes.
A: All right, I'll ask Tom to go with me.Is Tom 6_____ home?
B: Yes, he is. But he can't come today.His mother is ill.He 7_____ 8_____ go to the hospital
to 9_____ 10_____ his mother.
A: Oh, dear! Everyone is so 11_____. Well, I have 12_____ go home and do homework.
下图是100mgCaC2O4•H2O受热分解时，所得固体产物的质量随温度变化的曲线．
试利用图中信息结合所学的知识，回答下列问题：
（1）温度分别为t1和t2，固体产物的化学式为：A______，B______．
（2）由CaC2O4•H2O得到A的化学方程式为______．
（3）由A得B的化学方程式为______．
（4）由图计算产物C的分子量，并推断C的合理的化学式．
sterday my mother asked me to 5_____ my clothes.