单项选择题

Sulphur has occasionally been found in the earth in an almost pure state.

A. regularly
B. accidentally
C. sometimes
D. successfully
<上一题 目录 下一题>
热门 试题

单项选择题
Cement was seldom used in building during the Middle Ages.()

A. crudely
B. rarely
C. originally
D. symbolically
单项选择题
Some birds consistently return to the same nesting area each spring.
A. occasionally

B. purposely
C. regularly

D. surprisingly
相关试题