更年期内分泌最早变化的是

A．卵巢功能衰退

B．下丘脑功能退化

C．垂体功能退化

D．雌激素分泌增多

E．促性腺激素分泌下降

It is worth considering what it is ______ makes people happy in your life.   [ ]

A. when        

B. what            

C. which          

D. that