用括号内所给动词的适当形式填空，必要时可加助动词或情态动词。

    Last year my English class was difficult. First of all, it wasn't easy for me 1.______ (understand) the

teacher when she talked. 2.______ (begin)with, she 3.______ (speak) too quickly,and ! didn't understand every word. I was also afraid of 4.______ (speak) in class, because I thought my classmates 5.______ 

(laugh) at me. I 6.______ (make) complete sentences, either. Then I started to watch English-language

TV. It helps me a lot. Now I am enjoying 7.______ (learn) English and got an A this term.

1. _______2. _______3. _______4. _______5. _______ 6. _______7. _______

某企业正在考虑某设备的技术改造，设备原值k0为16000元，每年地裂化增加值为1000元。更新时假设无残值。

该设备技术改造时应遵循的原则是（）。

A.依据技术改造计划逐年进行

B.考虑实际情况，寻找适用的先进技术

C.必须以技术进步为前提

D.做到宏观经济效益和微观经济效益并重