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【单选题】
关于柴油机活塞环的叙述，不正确的是（）A.
主要采用的材料是可锻铸铁
B.
活塞环的硬度应比气缸套的硬度高10～20HB
C.
可采用耐磨铸铁
D.
可采用表面强化工艺改善表面性质
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【单选题】下列依次为上海、广东、福建、北京、四川名点小吃的是()。
A.
排骨年糕、黄桥烧饼、鼎边糊、艾窝窝、拔鱼儿
B.
小绍兴鸡粥、马蹄糕、土笋冻、小窝头、赖汤圆
C.
蟹壳黄、鸡仔饼、热干面、耳朵眼炸糕、钟水饺
D.
黄桥烧饼、娥姐粉果、凤梨酥、“都一处”烧麦、担担面
【单选题】About a century ago more people would not have appreciated the study of a foreign language as they do today. Gone are those days when patriotism towards one's own language was a major obstacle to lear...
A.
it was too difficult
B.
it was not allowed
C.
it was taught by foreign rulers
D.
it was seen as disloyalty
【简答题】完形填空。 People in many countries are learning English. Some learn at school, others study by 1 . A few learn English 2 the radio. Why do all these people want to learn English? It's difficult 3 that que...
【单选题】下列关于苷键的分类叙述错误的是( )
A.
根据所连单糖的个数可分为单糖苷 , 双糖苷等。
B.
根据生物体内的存在形式可分为 : 原生苷 , 次生苷。
C.
根据苷元的不同可分为 : 强心苷 , 皂苷。
D.
根据苷键原子可分为 : 氧苷 , 氮苷 , 硫苷 , 碳苷。
【简答题】language is a system of _________ ____ symbols used for human communication. 2. Linguistics is generally defined as the _______ study of ________. 3. If a linguistic study describes and yses the ...
【单选题】According to the records available, human beings have been engaged in the study of language for ______centuries.
A.
10
B.
15
C.
20
D.
25
【单选题】______ refers to the study and analysis of the mistakes made by second and foreign language learners.
A.
Contrastive analysis
B.
Error analysis
C.
Interlanguage
D.
The behaviorist approach
【简答题】双座止回阀输出端接气控二位三通阀控制端且二位三通阀有控制信号时,气源截止,则该组阀件的逻辑关系是 。A. 与门 B. 或门 C. 或非门 D. 与非门
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