对中性点不接地系统的10kV架空配电线路单相接地时（）。A.会造成速断跳闸 B.会造

第二节根据对话内容，从对话后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

W：Do you have any plans for your future?

M：Er,小题1:

W：That’s great! I’d like very much to go to Beijing．Maybe I’11 find a job there.

M：That’s not bad 小题2:

W：What? Are you kidding? It’s such a good chance to go abroad．

M：You know,小题3: And if I go there, my mom will go there ,too. I have to live with them.

W： 小题4: But so many students envy your chance.

M：I see． 小题5: You have your own say on your future while I am sort of controlled by my parents.

W：Poor you! Anyway，I think what your parents do is all for your own good．

A．but I envy you．                 B．You mean you have no freedom?

C．What about you?                 D．But I may change my mind．

E．my father’s there．               F for the moment I plan to go to France for my MBA．

G gook luck for your future．

某网络计划中，工作M的自由时差为3天，总时差为5天。通过检查分析，发现该工作的实际进度拖后，且影响总工期2天。在其他工作均正常的前提下，工作M的实际进度拖后（）。

A.5天

B.7天

C.6天

D.9天

商品储存的目的之一是为了（）。

A.防止积压

B.确保社会再生产顺利进行

C.商品保值

D.商品保鲜

简述石墨炉原子吸收光度法中常用基体改进剂的种类和作用有哪些。

先天性甲状腺功能减退的早期诊断。