B细胞淋巴瘤表达CD20的阳性率是（）。
A.90%
B.60%
C.80%
D.70%
E.90%以上
参考答案：E
这是什么交通标志？
A、两侧变窄B、右侧变窄C、左侧变窄D、桥面变窄
I found him sitting in his chair，completely ____ a magazine．
A．absorbing
B．being absorbed in
C．absorbed in
D．absorbing in
