—Tommy, _________ do you play the piano?

—When my mom is at home, I have to every day, but she’s away this week!

A．how about

B．how long

C．how much

D．how often

治疗首选

A．口服叶酸

B．口服维生素B₁₂

C．口服环孢素

D．口服雄激素

E．口服铁剂