[单项选择]There are many theories that _______ to be able to predict whether you will give birth to a girl a boy.
A. declare
B. claim
C. announce
D. state

[单项选择]How many theories does the author mention


A. One
B. Two
C. Three
D. Four

[单项选择]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 16 on the individual suggest that children engage in criminal behavior 17 they were not sufficiently penalized for previous misdeeds or that they have learned criminal behavior through 18 with others. Theories focusing on the role of society suggest that children commit crimes in 19 to their failure to rise above their socioeconomic status 20 as a rejection of middleclass values. Most theories of juvenile delinquency have focused on children from disadvantaged families, 21 the fact that children from wealthy homes also commit crimes. The latter may commit crimes 22 lack of adequate parental control. All theories, however, are tentative and are 23 to criticism. Changes in the social structure may indirectly 24 juvenile crime rates. For example, changes in the economy that 25 to fewer job oppor
A. return
B. reply
C. reference
D. response