世界近代竞技游泳大约开始于什么时期？（）A、19世纪初期 B、19世纪后期 C、19

若直线ax + y – 1 = 0与直线4x + (a – 5) y – 2 = 0垂直，则实数a的值等于  ．

下列离子方程式正确的是  (　　)

A．氢氧化钡溶液与等物质的量的稀H₂SO₄混合：Ba^2＋＋OH^－＋H^＋＋SO===BaSO₄↓＋H₂O

B．氨气通入醋酸溶液中：CH₃COOH＋NH₃===CH₃COONH₄

C．碳酸氢钙溶液中加入过量的氢氧化钠溶液：HCO＋OH^－===CO＋H₂O

D．澄清石灰水与盐酸反应：H^＋＋OH^－===H₂O

B

She went back to China to study journalism at Peking University. She is also 45 ________________ a sports program about the 2008 Beijing Olympics. She even hopes to 46 _______________ table tennis in the special 47 _______________ for disabled people in 2008 .She tells people that she likes to think about positive things and stay optimistic. She believes that keeping busy helps her to stay 48 _______________.

按照现行会计制度的规定，下列各项中，股份有限公司应作为无形资产入账的是 ( )

A．开办费

B．广告费

C．获得土地使用权支付的土地出让金

D．开发新技术过程中发生的研究费

肺内干酪样坏死灶液化并经支气管排出形成

A．窦道
B．糜烂
C．空洞
D．瘘管
E．溃疡