Scientists have advanced many theories about why human beings cry tears , none of ______ has been proved.
（A）whom
（B） which
（C） what
（D） that
查看解析
参考答案
继续答题：下一题
更多高中英语试题
- 1The newcomer went to the library the other day and searched for ______ ， he could find about Mark Twain.
- 2—_______ the forest park is far away，a lot of tourists visit it every year.
- 3The exact year ______ Angela and her family spent together in China was 2008.
- 4From space，the earth looks blue. This is _____ about seventy-one percent of its surface is covered by water.
- 5______the students came from different countries, they got along quite well in the summer camp.
- 6Care of the soul is a gradual process _______ even the small details of life should be considered.
