结肠癌最常转移到（）
A.肺脏
B.脑
C.肝脏
D.脊椎骨
E.前列腺
参考答案：C
You will fail your next exam ______ you start to work hard at your study now.
A．because
B．unless
C．so
D．if
付机（发电柴油机）试车操作规程？
