．如图，有一个形如六边形的点阵，它的中心是一个点，作为第一层，第二层每边有两个点，第三层每边有三个点，依次类推，如果层六边形点阵的总
若，证明：关于与方程 中，至少有一个方程有实数根。
在“重走北伐路”的学生夏令营活动设计中有悖历史常识的是（ ）A. 游览汀泗桥、贺胜桥，感受叶挺独立团的英勇善战B．走进曾一度成为全国革命
Commencement (毕业典礼)is a time for idealism. But economic reality is cruel everywhere; especially for new college graduates. They have been told repeatedly that a college degree is an open sesam
Tom did not take away the camera because it was just the same camera ____ he lost last week. A. which B. that C. whom D. as
My friends didn’t tell me ________ .A．which room he lived inB．which room he lived C．which room did he live linD．which room does he live in
著名学者余秋雨曾写了一段优美的文字：“就在秦始皇下令修长城的数十年前，四川平原上已经完成了一个了不起的工程，它的规模从表面上看远不如
下列国家中与我国陆上接壤的是( ) A．白俄罗斯 B．日本 C．印度 D．乌兹别克斯坦
