21.The two cities have reached an ______ to develop science and technology.
A．agreement B．education C．excitement D．invention21世纪教育网
( )22.Although it was very cold in winter，the snake was still ______.
A．alive B．afraid C．lonely D．clever
( )23.—Have you known Dr.Jackson for a long time?21cnjy.com
—Yes，since he ______ the Chinese Society.
A．joins B．has joined C．joined D．had joined
( )24.—Hobo and Eddie ______ the cinema to watch the film Zootopia.
—Oh，that's why I can't find them now.
A．have gone to B．have been to C．has gone to D．has been to
( )25.______ he ______ I am going to see the film tonight because we are busy.
C．Not only；but also D．Neither；nor
( )26.Even a drop of water ______ because it is so important to all the living things.
A．must waste B．must be wasted
C．mustn't waste D．mustn't be wasted