从所给的四个选项中，选择最合适的一个填入问号处，使之呈现一定的规律性。

考虑如下代码：

class Tree{}

class Pine extends Tree{}

class Oak extends Tree{}

public class Forest {

public static void main(String[] args ) {

Tree tree = new Pine();

if(tree instanceof Pine )

System.out.println("Pine" );

if(tree instanceof Tree )

System.out.println("Tree" );

if(tree instanceof Oak )

System.out.println("Oak" );

else

System.out.println("Oops" );

}

}

则输出结果中有哪些？

A.Pine B.Tree C.Forest D.Oops E.无输出

A、rose and palm

B、rose and oak

C、tulip and oak

D、tulip and palm

The red, orange and yellow lights contain ______.

A．less heat than the other lights

B．more heat than the other lights

C．a great deal of heat

D．a little heat

undred years？

A．To explain why it is likely that the Nightcap Oak population will increase in the future

B．To point out that the Nightcap Oak"s limited reproductive success has not led to a decrease in its population

C．To present evidence that the Nightcap Oak is able to tolerate major changes in its environment

D．To point out that the Nightcap Oak is able to resist diseases that have destroyed other tree species

A、They live in the houses as most people do in the city.

B、They live in the wikiups made of tree saplings.

C、They live in the teepees covered with buffalo hide.

D、They live in the wikiups made of tree saplings as well as teepees covered with buffalo hide.

ow. Change the form if necessary. olive tree; poplar; pine; Chinese fir; oak; teak; eucalyptus; Pinus patula __________ which can be used to make furniture or boatbuilding, is a tropical hardwood species placed in the family Lamiaceae.

A、general tree

B、full binary tree

C、binary tree

D、complete binary tree

A、snowy mountain peaks

B、tree fringed lakes

C、broad water meadows

D、the Dead Sea