哪类药物用于减少其加重或反复发作最好A．抗凝药 B．扩容剂 C．脱水剂 D．扩血管药

读出下面各数．

603000700读作：______

59080300读作：______

8500000000读作：______．

在一定的时间内，引起细胞兴奋或产生动作电位的最小刺激强度称为（）

A.阀刺激

B.阀强度

C.阀电位

D.阀值

E.峰电位

2007年粮食种植面积10553万公顷，比上年增加70万公顷；棉花种植面积559万公顷，增加7万公顷；油料种植面积1094万公顷，减少60万公顷；糖料种植面积167万公顷，增加10万公顷。
全年粮食产量50150万吨，比上年增加350万吨，增产0.7%，其中，夏粮产量11534万吨，增产1.3%；早稻产量3 196万吨，增产0.3%；秋粮产量35420万吨，增产0.6%。
全年棉花产量760万吨，比上年增产1.3%。油料产量2461万吨，减产42%。糖料产量11110万吨，增产11.4%。烤烟产量239万吨，减产3.9%。茶叶产量114万吨，增产10.9%。
全年肉类总产量6800万吨，比上年减少3.5%。其中，猪肉减少9.2%；牛、羊肉分别增长6.1%和5.8%。全年水产品产量4737万吨，增长3.3%。全年木材产量6974万立方米，增长5.5%。
全年新增有效灌溉面积107万公顷，新增节水灌溉面积136万公顷。

2006年全国的粮食总产量是多少万吨( )

A．50 150

B．49 800

C．50 500

D．50 350

Many theories concerning the causes of juvenile delinquency(crimes committed by young people) focus either on the individual or on society as the major contributing influence. Theories (91) on the individual suggest that children engage in criminal behavior (92) they were not sufficiently penalized for previous misdeeds or that they have learned criminal behavior through (93) with others. Theories focusing on the role of society suggest that children commit crimes in (94) to their failure to rise above their socioeconomic status, (95) as a rejection of middle, class values.
Most theories of juvenile delinquency have focused on children from disadvantaged families, (96) the fact that children from wealthy homes also commit crimes. The latter may commit crimes (97) lack of adequate parental control. All theories, however, are tentative and are (98) to criticism.
Changes in the social structure may indirectly (99) juvenile crime rates. For example, changes in the economy that (100) to fewer job opportunities for youth and rising unemployment (101) make gainful employment increasingly difficult to obtain. The resulting discontent may in (102) lead more youths into criminal behavior.
Families have also (103) changes these years. More families consist of one-parent households or two working parents; (104) , children are likely to have less supervision at home (105) was common in the traditional family (106) . This lack of parental supervision is thought to be an influence on juvenile crime rates. Other (107) causes of offensive acts include frustration or failure in school, the increased (108) of drugs and alcohol, and the growing (109) of child abuse and child neglect. All these conditions tend to increase the probability of a child committing a criminal act, (110) a direct causal relationship has not yet been established.

A．return

B．reply

C．reference

D．response

地基变形的p-s曲线有明显转折点的地基破坏形式是______。