雷达天线是定向圆周扫描天线，在水平面内，天线辐射宽度只有（）左右。
A．1°
B．2°
C．3°
D．4°
参考答案：A
—What did Yang Ying say?
—She said they _____ a school trip the next weekend. [ ]
A. will have
B. had
C. would have
D. have
将挥发油与邻苯二甲酸酐反应后，经酸碱处理，再进行皂化反应，其乙醚萃取物为
A．酸性成分B．碱性成分C．中性成分D．醇类成分E．醛酮类成分
