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

Two fifth…is

Two fifth…are

Two fifths…is

Two fifths…are

Every possible means ________ to prevent the air pollution, but the sky is still not clear．

is used

are used

has been used

have been used

________ he came, he would bring us a lot of flowers．

Every times

One time

Every time

Once a time

________ it was late, she went on working．

Though

Because

Since

Whether

He was ________ weak ________ he couldn't stand up．

such, that

so, that

very, that

so, as to

They worked hard ________ they finished their work ahead of time．

so

so that

such that

so as to

I wonder if he ________ us, and I think if he ________ us we'll be able to complete the task ahead of time．

helps, helps

will help, helps

helps, will help

will help, will help

You won't succeed ________ harder．

unless you will work

unless you work

unless you don't work

if you won't work

________ weather permits, we'll have an outing．

For

Though

While

If

We will go ________ the Party wants us to go．

wherever

there

to the place

which