The passage mainly discusses ______.A．the development of art historyB．the difference betwe

This passage mainly discusses ______ .A．the functions of carbon dioxide and waterB．the rol

The passage mainly discusses______.A．why the change of meat-eating habit matters muchB．how

The passage mainly discusses about______.A．business competitionB．buyers and sellersC．busin

The passage is mainly written to______.A．discuss how people view a new inventionB．analyze

This passage mainly discusses ______.A．two techni

The passage mainly discusses ______.A.the necessity of social changeB.certain factors that