牙石的致病原理为A．机械刺激牙龈 B．引起口臭 C．附着大量菌斑 D．导致颈部龋 E 发布时间：2017-06-02 14:50 │ 来源：www.tikuol.com 题型：单项选择题 问题： 牙石的致病原理为A．机械刺激牙龈B．引起口臭C．附着大量菌斑D．导致颈部龋E．引起色素沉积
题型：单项选择题 完形填空。 Bob wants to get some money. He finds a job at a shop. Every day he 1 some work after school.But 2 Saturday he works 3 day. Every day after school, he takes a bus to the shop. He 4 thereat 4:00. At the shop he cleans and washes vegetables, 5 , then puts them in bags. 6 he sweeps thefloor. Bob likes his work. He works 7 4 to 6.Then he goes home. He 8 supper at half past six.After supper he studies. He is usually tired 9 , 10 he goes to bed early. ( )1. A. finishes ( )2. A. on ( )3. A. the ( )4. A. gets ( )5. A. eats them ( )6. A. Some time ( )7. A. at ( )8. A. eat ( )9. A. before the night( )10. A. So B. does B. in B. other B. gets to B. puts away them B. Sometime B. on B. has B. after school B. But C. gets C. for C. all C. comes C. waters them C. Sometimes C. from C. does C. before supper C. For D. has D. at D. a D. comes to D. puts them away D. / D. between D. have D. at night D. And 查看答案