There isn't any difference between the two. I really don't know _______.
A：where to choose
B：which to choose
C：to choose what
D：to choose which
用锯锯木头，锯条的温度会升高．这是利用____ 的方法改变锯条内能的过程．
—Mary, ______ are my parents.
作为网络游客，要想保护自己，我们应该 （ ）
As soon as he heard the news , he burst out ____ (cry).
