单项选择题

In a sense, farmers began primitive genetic engineering (at the dawn of) agriculture, (which) they kept seeds (from) their best plants, gradually (improving) the quality of successive generations.

A．at the dawn of
B．which
C．from
D．improving
<上一题 目录 下一题>
热门 试题

单项选择题
Students (completing) a course in computer science and technology can (look forward to) (find) a wide (range) of jobs.
A．completing
B．look forward
C．find
D．range
单项选择题
(Despite of) diligent effort to promote domestic production during the war years, the Continental Army (had to rely) primarily on (captures) and imports for (much) of its military hardware and even for clothing.
A．Despite of
B．had to rely
C．captures
D．much
相关试题