问题
选择题
Scientists observe ___ making the most of our senses when we are young can keep us healthy later on in life.
A．if
B．what
C．that
D．When
答案
答案：C
考查从句关系词的选择。根据句子结构可知observe后面的是宾语从句，从句中不缺少成分，所以选择that，if意为是否 what作主语或者宾语 when作时间状语