适合95%的人群使用的座椅高度，应选的座臂高的百分位数为（）。
A.5%
B.10%
C.50%
D.90%
参考答案：A
The flu is believed _______ by viruses that like to reproduce in the cells inside the human nose and throat.
A．causing
B．being caused
C．to be caused
D．be have caused
A．
B．
C．
D．
