不懂的题??

98 10 29 Meridians of longitude and parallels of latitude form grid that can be used to locate the position of any point on the Earth's surface.

30Mercury and venus are the only planels in the solar system where do not have moons.(C)

Meridians of longitude and parallels of latitude form grid that can be used to locate the position of any point on the Earth's surface

第一，单数可数名词不能单独存在

第二，meridians和parallels形成的应该是grids

30Mercury and venus are the only planels in the solar system where do not have moons.(C)

第一，先行词是那两颗行星，所以where应该是that

第二，从后面的定语从句的结构看，从句缺乏主语，where明显不能做主语

对喔 ，谢啦