马赫数Ma等于()。
A.
B.
C.
D.
参考答案:B
解析:马赫数Ma定义。
I would like to buy the black pen because I ______that kind of pen ______well.
A.have told ;writes
B.was told;wrote
C.have been told;writes
D.have been told;is written
乳腺癌患者,当其 * * 皮内、皮下淋巴管被癌细胞阻塞时,可出现
A. * * 湿疹样变B. * * 局部皮肤凹陷C. * * 炎性表现D. * * 皮肤橘皮样变E. * * 凹陷