He did all he could to solve his own housing problem, ________ difficult it was．

A．however

B．no matter

C．whateve

D．although

Unlike watching TV, reading is a highly active process inside ________ it requires attention as well as memory and imagination．

A．until

B．but

C．unless

D．for

It is know to all that ________ you exercise regularly, you won't keep good health．

A．unless

B．whenever

C．although

D．if

－Did Jack come back early last night?

－Yes．It was not yet eight o'clock ________ he arrived home．

A．before

B．when

C．that

D．until

Allow children the space to voice their opinions, ________ they are different from your own．

A．until

B．even if

C．unless

D．as though

He tired his best to solve the problem, ________ difficult it was．

A．however

B．no matter

C．whatever

D．although

It was some time ________ we realized the truth．

A．when

B．until

C．since

D．before

You'd better take something to read when you go to see the doctor ________ you have to wait．

A．even if

B．in case

C．as if

D．in order that

She is good at maths ________ I feel a headache even thinking of it．

A．when

B．while

C．then

D．that

This is one of the best films ________ this year．

A．have been shown

B．that have shown

C．that have been shown

D．which has been shown