下列句子没有语病的一项是( )
A:四川省雅安市发生地震后,“企业公民”纷纷慷慨解囊,向灾区捐款的企业数量持续增加。
B:禽流感疫情出现20多天以来,我省家禽养殖业遭受重击,直接经济损失超过5亿多元。
C:有计划地利用疫苗进行预防接种,能够有效提高人群免疫水平,达到消灭乃至控制传染病的目的。
D:为了弘扬民族的传统养生文化,加多宝一直在不断丰富加多宝凉茶品牌。
馒头是我们的主食,其中的淀粉等大分子物质必须经过消化才能被人体吸收.人体内参与淀粉消化的消化液有( )
This is Mary's family. After dinner, Mary's mother talks on the phone. Mary's father watches TV. Mary's grandfather reads books. Mary's brother draws a picture. Mary plays with her teddy bear. They are a happy family.
⑴Mary's mother ____ A.
⑵Mary's father ____ B.
⑶Mary's grandfather ____ C.
⑷Mary's brother ____ D.
⑸Mary ____ E.
设x,y满足约束条件2x+y-6≥0x+2y-6≤0y≥0则目标函数z=x+y的最大值是( )