题目

Most  people  have  a hard  time  studying effectively (有效地)．__16__The following are some tips on how to study effectively. Consider the place and the time. When you wish to study effectively，consider the place and the time.__17__You can study at the place in which you are most comfortable.This will actually help you focus as you can associate (将……联系起来) the time and place every time you study.You can actually make it a habit to study at the usual place and time. __18_ Most of the time，people believe that coffee is the best drink to take while studying.They抗维生素D佝偻病属于X染色体显性遗传。一个患病男子与一个正常女子婚配，在进行遗传咨询时，你认为合理的建议是 [     ]A．不要生育B．只生男孩C．只生女孩D．妊娠期多补充钙