问题
选择题
Exactly when the first people arrived in ________ we now know as California, no one really knows.
A．which
B．what
C．that
D．it
答案
答案：B
考查宾语从句。宾语从句What we now know as California作为介词in的宾语。What引导起该宾语从句，在句中作为动词know的宾语。