在函数y=1x-5中，自变量x的取值范围是（ ） A．x≠5 B．x≠0 C．x＞5D

25 ℃时，有关物质的电离平衡常数如下：

回答下列问题。

（1）物质的量浓度为0.1 mol·L^－1的下列四种物质，pH由大到小的顺序是________（填编号）。

a．Na₂CO₃  b．NaClO

c．CH₃COONa  d．NaHCO₃

（2）常温下0.1 mol·L^－1的CH₃COOH溶液加水稀释过程中，下列各量一定变小的是________（填编号）。

A．c（H^＋）                   B．c（CH₃COO^－）

C．c（H^＋）·c（OH^－）        D．

（3）体积均为10 mL、pH均为2的醋酸溶液与HX溶液分别加水稀释至1 000 mL，稀释过程中pH变化如图所示。则HX的电离平衡常数________（填“大于”、“等于”或“小于”）醋酸的电离平衡常数，理由是__________________；稀释后，HX溶液中水电离出来的c（H^＋）________（填“大于”、“等于”或“小于”）醋酸溶液中水电离出来的c（H^＋），理由是_________________________________________________________________。

（4）25 ℃时，若测得CH₃COOH与CH₃COONa的混合溶液的pH＝6，则溶液中c（CH₃COO^－）－c（Na^＋）＝________（填精确数值）。

公安机关处于国内斗争的第一线，它所面对的( )。

A．是阶级矛盾、社会矛盾中最具有对抗性的部分

B．是危害性活动中最具有隐蔽性的部分

C．是污染社会行为中最具有腐蚀性的部分

D．是各种社会矛盾中最尖锐、最复杂的部分

正常儿可以独坐，但需双手在前支撑，脊柱略弯曲，呈拱背坐的月龄为（）。

A.3个月

B.4～5个月

C.6个月

D.7个月

E.8个月

An eight-year-old child heard her parents talking about her little brother. All she knew was that he was very sick and they had no money left. When she heard her daddy say to her (1) mother," (2) a miracle can save him now", the little girl went to her bedroom and took out her piggy bank. She (3) all the change out on the floor and counted it carefully. Then she (4) her way six blocks to the drugstore.

"And what do you want" asked the shopkeeper. "It’s (5) my little brother," the girl answered back. "He’s really, really sick and I want to buy a (6) . His name is Andrew and he has something (7) growing inside his head and my daddy says only a miracle can save him. " "We don’t (8) miracles here, child. I’m sorry." the chemist said, smiling (9) at the little girl.

In the shop was a (10) customer. He stooped down and asked the little girl, "What kind of miracle does your brother (11) " "I don’t know," she replied. "He’s really sick and mommy says he needs (12) . But my daddy can’t pay for it, so I have brought my (13) .""How much do you have" asked the man. "One dollar and eleven cents, (14) I can try and get some more," she answered quietly. "Well, what a coincidence," smiled the man. "A dollar and eleven cents—the (15) price of a miracle for little brothers. (16) me to where you live. I want to see your brother and (17) your parents. "

That well-dressed man was Dr Carlton Armp, a doctor. The operation was completed without any (18) and it wasn’t long before Andrew was (19) again. The little girl was happy. She knew exactly how much the miracle cost—one dollar and eleven cents—also the (20) of a little child.

17（）

A．ask

B．encourage

C．persuade

D．meet

甲市某执法大队在对张某涉嫌非法营运的检查过程中，认定张某驾驶小客车，载客三人，该车无营运证，涉及非法营运。执法人员遂依据该市《出租汽车管理条例》当场对涉嫌非法营运的车辆予以暂扣，并出具《暂扣、扣押物品凭证》及《处理告知书》。

关于执法人员暂扣张某车辆，下列说法正确的是（）。

A.扣押应当由法律规定的行政机关实施

B.扣押应当由法律、行政法规规定的行政机关实施

C.扣押应当由法律、法规规定的行政机关实施

D.行政机关可委托具有管理公共事务职能的组织实施扣押