The last river ________ they crossed is two miles wide．

A．where

B．which

C．that

D．in which

The place ________ you are going to visit is the ruin of a place．

A．in which

B．at which

C．where

D．which

________ is natural, he married Mary．

A．It

B．What

C．Which

D．As

His father died last year, ________ made it impossible for him to go abroad．

A．when

B．which

C．as

D．that

The scientists were waiting to see the problem ________．

A．settle

B．settled

C．to settle

D．settling

The foreigner tried his best, but he still couldn’t make his point ________．

A．understand

B．understanding

C．to understand

D．understood

People ________ in the city do not know the pleasure of country life．

A．live

B．to live

C．lived

D．living

The ________ price will save you one dollar for each dozen．

A．reduce

B．reducing

C．reduced

D．reduces

He went from door to door, ________ waste papers and magazines．

A．gathering

B．gathered

C．gather

D．being gathered

The book is worth ________．

A．seeing

B．reading

C．seen

D．read