- Mr. White, will you please teach me how to perform pair skating today?

--         . You have to practise single skating well first.

A．Two heads are better than one.

B．Think twice before you do.

C．Learn to walk before you run.

D．One today is worth two tomorrows.

肠原型紫绀的解救方法为（）。

A.高压氧舱

B.补液利尿

C.静注亚甲蓝

D.注射抗生素

E.补充碳酸氢钠