问题

Theworkershaveproduced_______thisyearastheydidtwoyearsago
A:astwicemuchcotton
B:twiceasmuchcotton
C:twicecottonasmuch
D:cottontwiceasmuch
B:twiceasmuchcotton
C:twicecottonasmuch
D:cottontwiceasmuch
正确答案是: