Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in the following question.
It was an old motorbike which my brother bought from our neighbor.
A.which
B.an old
C.It
D.bought from

Mark the letter A, B, C or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
It was in 1896 in Athens, Greece where the first modern Olympics were held.
A.in 1896
B.where
C.It
D.were

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
It is not your hard work which we are questioning.
A.which
B.is not
C.hard work
D.questioning

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
It was at our latest meeting when I found out Louisa had passed away.
A.when
B.had passed away
C.found out
D.It was

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
It was in last December when I noticed that he seemed to be a bit depressed.
A.was
B.when
C.depressed
D.to be

Điền số thập phân thích hợp vào ô trống
3,78km =  m
A.3780
B.
C.
D.

Đới nào có tốc độ đô thị hoá cao trên thế giới hiện nay?
A.Đới nóng.
B.Đới lạnh.
C.Đới chí tuyến.
D.Đới ôn hòa.

Điền đáp án đúng vào ô trống
Trong một cuộc thi chạy tiếp sức, bạn An chạy được 100m, bạn Bình chạy được 11,3dam, bạn Hòa chạy được 0,154km. Hỏi bạn nào chạy được quãng đường dài nhất?
Bạnchạy được quãng đường dài nhất.
A.Hòa
B.
C.
D.

Dãy các muối đều phản ứng với dung dịch $ Ba{{\left( HC{{O}_{3}} \right)}_{2}} $ là:
A.$ NaN{{O}_{3}},KN{{O}_{3}} .$
B.$ N{{a}_{2}}C{{O}_{3}},CaC{{O}_{3}} .$
C.$ {{K}_{2}}S{{O}_{4}},N{{a}_{2}}C{{O}_{3}} .$
D.$ NaHC{{O}_{3}},MgC{{O}_{3}} .$

Muối hiđro cacbonat là muối chứa gốc 
A.$ -C{{O}_{2}} .$
B.$ -{{H}_{2}}C{{O}_{3}} .$
C.$ -C{{O}_{3}} .$
D.$ -HC{{O}_{3}} .$