We believe one belt，one Road （一带一路 ）will help China improve the with lots of countries．（ ）
A．relationshipB．situation
C．environment
I still haven't found my pet dog．
I'm sorry to hear that．You______ be very sad．（ ）
A．canB．shouldC．mustD．will
Why did she______your invitation？
Because she had an important meeting to attend that day．（ ）
A．turn downB．put awayC．look upD．hand in
Her father tried to______ that nothing unusual had happened．
In fact，it was not serious．（ ）
A．imagineB．pretendC．meanD．warn
Look，the boss is very angry with Alex．
Well，he came late again．But that's no______ to shout at him．（ ）
A．problemB．lessonC．excuseD．Reason
Are you alone？I just want a______ word with you．（ ）
A．singleB．newC．privateD．certain