工程建设项目招标代理机构，由( )负责其资格认定。 A．商务部 B．国家发改委

小便频数，色清，量多，伴腰膝冷痛者，多见于

A．膀胱湿热证
B．小肠实热证
C．肾阳虚证
D．肾气不固证
E．肾气虚证

额骨的阴影是一种（）的表现。

A.病态

B.衰老

C.年轻

D.立体感

Which of the following is true of world steel production
a. The steel industry still has a bright prospect on a global scene.
b. Steel consumption in the world registered a drastic cut.
c. Steel makers are drastically cutting down their production.
d. Better promotion is needed for improving sales of steel products.

结合下图分析汽车起动时的同步喷油量控制原理？