来自刘清君的问题
3.—IsDoctorWang____UNICEFvolunteer?—Noheis____ORBISdoctor.Hehasworkedforitforyears.A.a;anB.an;aC.an;anD.a;a
3.—IsDoctorWang____UNICEFvolunteer?
—Noheis____ORBISdoctor.Hehasworkedforit
foryears.
A.a;an B.an;a
C.an;an D.a;a
