9. Studyies show that young people with higher-than-average blood pressure and their families have a history of high blood pressure are more likely than others to develop a severe form of the condition.
正确答案:whose families have a history of high blood pressure.
为什么A不对,不够简洁吗?
21 Most teen-agers who work for pay hold jobs that requir few skills,(carry litte responsiblity,and offer no hope for career advancement).
上面已是正确答案,但想问一下:如果改成that requir few skills, litte responsibility and no hope for carreer advacement可以吗?