()不是产生在摩擦面的接触中,而是产生于润滑油的内部。
A、干摩擦
B、液体摩擦
C、边界摩擦
D、混合摩擦
参考答案:B
50岁女性,右侧腮腺无痛进行性肿大,有类风湿性关节炎史,γ球蛋白增高,活检有大量淋巴细胞。最可能的诊断是()
A.慢性化脓性腮腺炎
B.舍格伦综合征
C.腮腺多形性腺瘤
D.腮腺淋巴结核
E.腮腺放线菌病
句型转换。
1. He knows a little about Chinese. (提问)
_____ _____ does he know about Chinese?
2. Jack's mother gives him ten dollars every day. (提问)
_____ _____ _____ _____ Jack's mother give him every day?
3. There are two cups of tea on the table. (提问)
_____ _____ _____ _____ tea on the table?
4. There is an apple in the picture. (提问)
_____ _____ in the picture?
5. There is an apple in the picture. (提问)
How _____ _____ _____ there in the picture?