The mother often tells her son to be a good boy，warning him to（）trouble.

单项选择题You（）things about.Look，what a mess in your room!

A.always throw
B.have always thrown
C.are always throwing
D.had always been throwing

单项选择题On the physical level，massage aids the elimination of （）wastes （often the cause of muscle aches and pains）by stimulating blood circulation.

A.excessive
B.poisonous
C.toxic
D.deadly

单项选择题My dream hometown is an amazing place（）any pollution.

A.with
B.without
C.out
D.in

单项选择题We are preparing （）art festivals.

A.on
B.in
C.for
D.of

单项选择题It is reported that a lot of adults take lessons online （）further education.

A.after
B.to
C.with
D.for

单项选择题The teachers hope all of us can hand （）our homework（）time every day.

A.up；in
B.out；on
C.on；in
D.in；on

单项选择题It is（）good exhibition that I have seen it several times.

A.so
B.such
C.so a
D.such a

单项选择题By the time he got up，he found his father （）to work.

A.went
B.have gone
C.gone
D.had gone

单项选择题I think I have （）my key in the car.

A.forget
B.left
C.forgotten
D.leave

单项选择题（）our surprise,he failed the math exam.

A.In
B.On
C.To
D.At