Leaders of the BRIC countries-----Brazil, Russia, India and China----_______their second summit on Friday. President Hu Jintao then returned home to help direct relief work ______the deadly earthquake in Qinhai.

A．left, to follow

B．concluded, following

C．had left, following

D．had concluded, followed

婴儿期扁桃体炎少见的原因是（）

A.咽部狭窄

B.咽鼓管宽、直、短，呈水平位

C.腭扁桃体至1岁末逐渐增大

D.咽部方向垂直

E.婴儿非特异性免疫功能差