In Viet Nam, you shouldn't ________ at somebody's house on the first day of the New Year unless you have been invited by the house owner.

B. Plastic bags are often used because of their convenience.

C. Importing plastic waste from developed countries makes the problem more sophisticated.

D. The governments do not prohibit the use of plastic bags at the stores.

A. increases the cost of products.

C. is indispensable in almost all activities of the modern world.

D. is replaced by other alternatives in producing plastic bags.

A. Plastic bags should be limited as much as possible to save the Earth from their harmful impacts.

B. Each individual should reuse their plastic bags to save money for other purchases.

C. The governments should cooperate with every citizen in cleaning the plastic bags in the polluted oceans.

D. It is easier to keep the environment clean at first than to save it after it is polluted.