单项选择题
What kinds of things have activists done to protect research animals（）
A．Set them free. B．Damage the labs. C．Sent threatening letters. D．All of the above.
单项选择题 The purpose for the activists to be against researchers is （）
单项选择题 What will happen if the researchers don't meet the demands made in the letter from the activists（）
单项选择题 The police think that use of violence by animal rights groups is（）
