【单选题】The waiter' face, tanned to a dark brown and deeply wrinkled, reminded Suchen of a walnut shell, yet his eyes, even in the dim light, with alertness, like the eyes of a mountain lion.
【简答题】One day I was doing a big cleanup when I ____ a knotted handkerchief with an old dark brown coin inside.I took one look and immediately ___ a forgettable time. In 1991,I had spent five months in Nige...
【单选题】Individuals of a particular species of ground beetle are either light tan or dark brown. Light-tan beetles are predominant in habitats with light-colored sandy soils, and dark-brown beetles are predom...
A.
The reproductive success of beetles in habitats with sandy soils is greater than that of beetles in habitats with loam soils.
B.
Insectivorous birds prefer to eat light-tan beetles rather than dark-brown beetles.
C.
Ground beetles have higher rates of survival in habitats with loam soil.
D.
Insectivorous birds are predators of this species of ground beetle.
【单选题】Assume that in guinea pigs (豚鼠) , dark brown fur (B) is dominant to black fur (b). If you mate a homozygous black guinea pig with a heterozygous brown guinea pig, what proportion of the progeny will b...