They feared that he would _____ if he continued to work on the project day and night.   [ ]

A. burn himself down    

B. burn himself out    

C. burn himself up

D. burn himself off

工程概算审计介入的有效时点应该是（）。

A.建设阶段

B.竣工阶段

C.初步设计阶段

D.可研阶段