Để tách riêng Fe2O4 ra khỏi hỗn hợp BaO và Fe2O3 ta dùng:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 34 to 40

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer
Ha Long Bay, located in Quang Ninh Province, Viet Nam, was recognized as a World Heritage Site by UNESCO in 1994. Over the years, Ha Long Bay has attracted numerous visitors who come to enjoy its

A. releasedB. laughedC. weighedD. looked

A. admireB. excitedC. historicD. recognize

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks

Read the following announcement and mark the letter A,B,C, or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks from 15 to 17

Read the following announcement and mark the letter A,B,C, or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks from 12 to 14