【简答题】A.She can help the man take care of the plants. B.Most plants grow better in direct sunlight. C.The plants need to be watered frequently. D.The plants should be placed in a shady spot.
【单选题】The evolution of sex ratios has produced, in most plants and animals with separate sexes, approximately equal numbers of males and females. Why should this be so? Two main kinds of answers have been o...
A.
conducted their research at approximately the same time
B.
sought to manipulate the sex ratios of some of the animals they studied
C.
sought an explanation of why certain sex ratios exist and remain stable