面对不断走低的楼价,购房者站在楼前(),他们因为憧憬更大的降价空间而愈加()不定。
A.徘徊;忧郁
B.忧郁;困惑
C.徘徊;犹豫
D.犹豫;困惑
参考答案:C
________ by the problem that was put forward at the meeting, the people in the audience had
________ looks on their faces. [ ]
A. Puzzled;puzzling
B. Puzzled;puzzled
C. Puzzling;puzzling
D. Puzzling;puzzled
同位素示踪法可用于反应机理的研究,下列反应或转化中同位素示踪表示正确的是()。
A.选项A
B.选项B
C.选项C
D.选项D