【C14】A．forestB．vegetationC．plantsD．trees

A．policeB．trafficC．petsD．trees

下列命令属于外部命令（)A.DATEB.COPYC.TYPED.TREE

【C4】A．producesB．createsC．plantsD．manufactures

What does the passage mainly talk about？A．The three benefits brought by trees.B．Trees and

According to the passage, what is the best choice of Christmas trees？A．A real tree that is

It is believed that the tradition of having a pine tree as a Christmas Tree comes fro