The moment we heard the news of the earthquake, we began to ________ the work to rescue those who were trapped in the building.

A．set off

B．set down

C．set aside

D．set about

哪些酶缺陷可导致苯丙酮尿症()

A．二氢生物蝶呤还原酶

B．鸟苷三磷酸环化水合酶

C．苯丙氨酸羟化酶

D．酪氨酸酶

E．碱性磷酸酶