--- I ____ so busily recently that I ____ no time to help you with your maths.

---That’s OK. I can manage it by myself.

A．had been working; had had

B．have been working; had

C．have been working; have

D．am working; will have

患儿，男，6个月，自幼口唇紫绀，心率126次／分，律齐，胸骨左缘第2肋间可闻及3～4／6级连续性杂音，P2不亢进。经皮血氧饱和度84%。

患儿就诊时需进行的常规检查有（）

A.动态心电图

B.心脏PET

C.左右心室造影

D.心脏MRI

E.胸部X线平片

F.超声心动图

G.心电图