—Do you often help your cousin with his English?

—No. He learns English _______.

A．by himself

B．for himself

C．with himself

D．on himself

下列哪种肝炎病毒基因组为DNA

A．甲型肝炎

B．乙型肝炎

C．丙型肝炎

D．丁型肝炎

E．戊型肝炎