在经常刮大风的海岛上,无翅或残翅的昆虫较多。产生这种现象的主要原因是
A.不适应的结果
B.自然选择
C.人工选择
D.遗传和变异
答案:B
在经常刮大风的海岛上,无翅或残翅的昆虫较多。产生这种现象的主要原因是
A.不适应的结果
B.自然选择
C.人工选择
D.遗传和变异
答案:B
A. books
B. boxes
C. rooms
2. She wants to take them to the . [ ]
A. bedroom
B. house
C. classroom
3. Can Li Ming help Miss Wang?[ ]
A. Yes, he is.
B. Yes, he can.
C. No, he can't.
4. Li Ming puts the books in small boxes.[ ]
A. three
B. four
C. five