请教：OG-10：175

熏依草

Parasitic wasps lay their eggs directly into the eggs of various host insects in exactly the right numbers for any suitable size of host egg.If they laid too many eggs in a host egg,the developing wasp larvae would compete with each other to the death for nutrients and space.If too few eggs were laid ,portions of the host egg would decay,killing the wasp larvae.

Which of the following conclusions can properly ba drawn from the information above?

A The size of the smallest host egg that a wasp could theoretically parasitize can be determined from wasp's egg-laying behavior .

B

C Parasitic wasps learn from experience how many eggs to lay into the eggs of different host species.

答案是A，我选的C，NN解释下吧

mbz

C is possible, but it is not mentioned in context, so it is not related.

A is right. look at the words: in exactly the right numbers for any suitable size of host egg

Let me give you an example, a + 5 =b:

If we know from observation that when a=6, b=11, when a=4, b=9, then we can come up with a conclusion that when a=1, b=6.

a is the number of wasp's egg, and b is the size of the host egg .

Does that help?

熏依草

GG'explanation is good ,but I find it still difficult to rule out C ,because i mainain the disadvantages for  Parasitic wasps lay their eggs in an improper way may let them learn from experience how many eggs to lay into the eggs of different host species.

will you please explain C more accurately ?

thanks so much!

mbz

C is irrelevant b/c the statement that Parasitic wasps learn from experience has not been mentioned at all.

[此贴子已经被作者于2006-6-20 12:22:03编辑过]