Such poets as Shakespeare _____ widely read, of whose works, however, some _____ difficult to understand.

[ ]

A. are; are

B. is; is

C. are; is

D. is; are

甲、乙两个同一专业的施工单位分别具有该专业二、三级企业资质，甲、乙两个单位的项目经理数量合计符合一级企业资质要求。甲、乙两单位组成联合体参加投标，则该联合体资质等级应为（）

A.一级

B.二级

C.三级

D.暂定级