在吸声材料中,穿孔板的共振频率,与下列哪几种情况有关()。A.板的密度 B.板的流阻

题型:多项选择题

问题:

在吸声材料中,穿孔板的共振频率,与下列哪几种情况有关()。

A.板的密度

B.板的流阻

C.板的穿孔率

D.穿孔板的孔径

E.穿孔板厚度

考点:土木建筑工程建筑装饰构造建筑装饰构造题库
题型:多项选择题
下列方程组中不是二元一次方程组的是(  )
A.
x-2y=1
3x+y=5
B.
xy=1
3x+y=1
C.
x+8=4
3x+y=1
D.
x+8=4
y=3
题型:多项选择题

人体血液中钾元素含量偏低,将会影响到肌肉和神经功能。可表现为身体乏力,精神恍惚,医学上称为低血钾症。医生在治疗时需要给病人补充钾元素。根据你学过的有关化学和生物知识,并结合你的生活经验判断,适合人体补充钾元素的一种化合物是[ ]

A.KCN(氰化钾)

B.K2O

C.KCl

D.KOH

题型:多项选择题

Stacy had recently moved from New York City to Stoneybrook, Connecticut. It was ___1___ for her to make new friends but she finally had three when she joined the Babysitters Club to ___2___ little children whose parents were busy. Claudia, Kristy, and Mary were in her class at school and also the other ___3___ of the club. The girls met at five o’clock on Fridays and waited for the ___4___ to ring. So far they had been busy, in spite of the ___5___ that they couldn’t stay out late and were under 13.

___6___, the girls’ world was invaded(侵犯) by a second group ___7___ themselves the Babysitters Agency. They were ___8___ and the group also included a few boys. The Babysitters Club tried to think of ways to ___9___ with the older group. They could clean and work for less money, however, they ___10___ it would be difficult to compete. The shock was even greater than they had ___11___ when most of their best customers started to call the new group. They ___12___ to get only a few jobs.

To try a new ___13___ Kristy recruited(招收) a few older kids who told the club they didn’t want to ___14___ their money with the other group. The club ___15___ only too quickly that these older girls joined only as spies and didn’t ___16___ for their job assignments(分派). Thus, more parents were ___17___ with the club.

Finally, the girls realized that the ___18___ in the other group were not good babysitters. They watched television, talked on the phone, and invited boyfriends to the house ___19___ they were sitting. When the children of the families started to ___20___, and a near accident almost occurred, the club went to the parents to tell them what was happening.

1. A. active     B. thoughtful       C. easy                         D. hard

2. A. take care of    B. run into                  C. go through              D. take advantage of

3. A. children  B. members                  C. circles D. players

4. A. alarm     B. traffic C. phone D. neighbor

5. A. fact B. degree C. question     D. demand

6. A. Therefore      B. Suddenly    C. Regularly                D. Unwillingly

7. A. attracting             B. finding       C. calling       D. matching

8. A. younger               B. cleverer      C. taller   D. older

9. A. compete B. fight   C. do      D. meet

10. A. heard    B. knew  C. promised    D. shot

11. A. damaged      B. caught C. expected     D. forced

12. A. hoped   B. liked   C. refused       D. seemed

13. A. chance  B. possibility  C. power D. policy

14. A. share    B. give    C. provide      D. mark

15. A. put down     B. paid off      C. found out   D. come through

16. A. check up      B. end up       C. look up      D. show up

17. A. satisfied       B. unhappy     C. curious       D. helpful

18. A. kids      B. adults  C. systems      D. situations

19. A. that      B. when  C. where D. how

20. A. blow    B. complain    C. appreciate   D. spread

题型:多项选择题

下列属于不明产权的房屋是( )。

A.无权属证明的

B.产权人下落不明的

C.暂时无法确定产权所有人的

D.有两个产权人的

E.产权关系正在诉讼的

题型:多项选择题

艾滋病属于下列哪种类型感染()

A.急性病毒感染

B.持续性病毒感染

C.慢性病毒感染

D.潜伏病毒感染

E.慢发病毒感染

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