光盘驱动器的核心装置是 ( )A．定位机构 B．驱动电路 C．光头装置 D．主轴驱动

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.

下列出疹性传染病最早出疹的疾病是（）。

A.麻疹

B.天花

C.猩红热

D.伤寒

E.水痘

临床上最常见的肛瘘类型是（）

A.经肛管括约肌型

B.肛管括约肌间型

C.肛管括约肌上型

D.肛管括约肌外型

E.骨盆直肠瘘

用行×列表卡方检验进行三个样本率的比较，若P＜0.05，则结论是

A．三个样本率各不相同
B．总体率之间两两有差别
C．至少有两个总体率有差别
D．各个总体率都相等
E．p₁、p₂、p₃不全相等或完全不相等

基坑（槽）四周排水沟及集水井应设置在（）。

A.基础范围以外

B.堆放土以外

C.围墙以外

D.基础范围以内