This new kind of chemicals will help keep the air, soil and water________ from pollution.
A.free | B.empty | C.loose | D.short |
Tony ______ his homework this morning before he went to school.
A.has done | B.did | C.has done | D.will do |
He was about to tell me the secret _______ someone patted him on the shoulder.
A.as | B.when | C.while | D.then |
E-mail, as well as telephones, _____ an important part in daily communication.
A.is playing | B.have played | C.are playing | D.play |
Hiking is ______ great fun. You will get close to ______ nature and take exercise at the same time.
A.a; the | B.a; / | C./; the | D./; / |
Police have not_______ the possibility ______ the boy was take by aliens .
A.ruled out; that | B.taken out; that |
C.made out; which | D.ruled out; what |