脾门处低回声光团最常见的是（）
A.淋巴结、肿瘤
B.血管
C.副脾
D.淋巴结、血管
E.血管、副脾
参考答案：C
Many beautiful buildings ______ in our city last year. [ ]
A. are built
B. were built
C. is built
D. was built
复制整个屏幕到剪贴板的方法是（）。
A．PrintScreen
B．Alt
C．Alt+PrintScreen
D．Ctrl+Alt+PrintScreen
