Liên kết đôi giữa hai nguyên tử cacbon gồm:
 
A.Hai liên kết \[\pi \]
B.Một liên kết \[\sigma\] và một liên kết \[\pi \]
C.Một liên kết \[\sigma\] và hai liên kết \[\pi \]
D.Hai liên kết \[\sigma\]

Trong phân tử hợp chất hữu cơ, cacbon có hóa trị
A.II
B.I
C.IV
D.III

Choose the word whose underlined part differs from the other three in pronunciation
A.visit
B.thick
C.lift
D.site

Choose the word whose underlined part differs from the other three in pronunciation
A.served
B.buried
C.prepared
D.ranked

Choose the word whose underlined part differs from the other three in pronunciation
A.wanted
B.recognized
C.located
D.visited

Choose the word whose underlined part differs from the other three in pronunciation
A.citadel
B.craftsman
C.complex
D.comprise

Choose the word whose underlined part differs from the other three in pronunciation in the following question.
A.couples
B.costs
C.presents
D.guests

Choose the word whose underlined part differs from the other three in pronunciation
A.stones
B.thieves
C.places
D.ensures

Choose the word whose underlined part differs from the other three in pronunciation
A.caves
B.memories
C.landscapes
D.itineraries

Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in the following question.
A.character
B.charity
C.church
D.cheap