MARK THE LETTER A,B,C OR D ON YOUR ANSWER SHEET TO INDICATE THE CORRECT ANSWER IN THEFOLLOWING QUESTION

Câu 14: Mark the letter A,B,C or D on your answer sheet to indicate the correct answer in thefollowing question.They'll be able to walk across the river……..A. when the ice will be thick enoughB. if the ice will be thick enoughC. if the ice is thick enoughD. unless the ice is thick enough