Please choose the correct answer to the question: An important rule for students to know when heating a test tube is to

Answer1: place a cork in the mouth of the test tube. Answer2: point the mouth of the test tube away from others. Answer3: hold the test tube loosely with the fingertips. Answer4: shake the test tube forcefully to keep contents mixed.

Answer format: answer1/answer2/answer3/answer4
Answer: answer2