---Tom studies very hard and is intelligent as well.

---______that he always gets the first place in all examinations.

A．No way

B．No wonder

C．No problem

D．No doubt

为明确诊断，做下列哪项检查最佳

A．食管吞钡X线检查

B．胃镜检查

C．B超检查

D．肝功能检查

E．腹部平片