高中英语主谓一致单选题

Half of the workers here ________ under 30 ________.

A．is;years

B．are;year old

C．is;years old

D．are;years of age

________ of the land in that district _______ covered with trees and grass.

A．Two fifth; is

B．Two fifth; are

C．Two fifths ; is

D．Two fifths; are

The teacher together with the students ________ discussing Reading Skills that ________ newly published in America.（）

A．

are; were

B．

is; were

C．

are; was

D．

is; was