单项选择题


A．if
B．once
C．when
D．whereas
<上一题 目录 下一题>
热门 试题

单项选择题
A．contributionB．deductionC．contemplationD．speculation
A．contribution
B．deduction
C．contemplation
D．speculation
单项选择题
Those studies carried out in North Carolina suggest that _________.
A．trees' function for absorbing carbon dioxide is limited
B．carbon dioxide is the main cause for global warming
C．leaves falling from trees can emit more oxygen
D．more carbon dioxide is beneficial for trees' growth for many decades
相关试题