下列物质中，属于纯净物的是（ ） A．石油 B．空气 C．臭氧 D．矿泉水

用所给动词的适当形式填空。

1. My father ______  (not have) lunch at home.

2. Let's ______ (do) it this afternoon, OK?

3. Listen. The children ______ (sing) English songs.

4. He often asks Jim ______  (go) shopping.

5. I have something ______  (do) today.

6. She usually ______  (do) her homework at home. But today she ______  (do) it at school.

    Now she ______  (do) it.

7. What drink ______  you ______ (want) to take?

8. Look! Those children ______ (play) football.

9. ______  (not forget) to do it this afternoon.

10. She ______  (have) to do her homework this evening.

利用职务上的便利为请托人谋取利益，收受请托人房屋、汽车等物品，未变更权属登记或者借用他人名义办理权属变更登记的，不以违纪论处。

关于凸行竖曲线最小半径，正确的是（）。

A.凸形竖曲线最小半径只需要满足离心加速的要求

B.凸形竖曲线最小半径只需要满足行车视距的要求

C.凸形竖曲线最小半径需要满足离心加速度和行车视距的要求

D.凸形竖曲线最小半径不需要满足离心加速度和行车视距的要求

下列哪种手术不属择期手术

A．胃十二指肠溃疡的胃大部分切除术B．甲状腺功能亢进的甲状腺次全切除术
C．下肢静脉曲张高位结扎术
D．先心病房间隔缺损修补术
E．贲门癌根治术

若PC100 SDRAM的数据传输率为800MB/S,则PC133 SDRAM的数据传输率为【 】MB/S。