The problem with people in Africa ____that the more is given and the more ______.

A．is; is needed

B．are; is needed

C．is; they need it

D．are; they need it

甲、乙、丙拟设立一有限合伙企业，甲、乙为普通合伙人，丙为有限合伙人，下列不可以作为丙的出资的是：（）

A.著作权

B.土地使用权

C.房屋租赁权

D.劳务