国营贸易项下的商品仅限于关系国计民生的某些重要商品，因此，国营贸易的经营范围具有指定的特点。 ( )
参考答案：对
尾焦不清理可以对炉门。
Some of my friends are interested in science, but none of them can tell ____________.
A．when UFOs appear next time
B．if horses know the way or not
C．where was this kind of plant found
D．how elephants communicate
