To protect the environment, the local government has ______ a lot of signs to warn the citizens not to litter the ground.
Mother bought me 3 books on English study, the second ________ I really liked.
– Your job ________ open for your return. – Thanks.
It is ________ that almost all the students like it.
Sentences can be ________ into clauses, and clauses into phrases.
I gave him a present but he gave me nothing ________