According to the survey, two thirds of the area__________covered by trees now and 90% of the population__________contributions to the Greening Project in the city.

A．is ; has made

B．are; have made

C．is; have made

D．are; has made

FIDIC 合同条件下，工程费用支付的必要条件之一是（ ）。

A．工程施工已经全部完成

B．承包商的工作使工程师满意

C．工程进度符合工程师的要求

D．变更项目已经工程师审核