—I just can’t stop worrying about the result of the English examination.

—___________.There’s nothing you can do but wait..

A．Take your time

B．Take it easy

C．Don’t mind

D．Don’t mention it

弱碱性阴离子交换树脂的离子交换基团是（）

A．-SO₃-H⁺

B．-COO-H⁺

C．-N+（CH3）3C^-

D．-NH₂

E．RP-18