一个等边三角形的边长为a，则它的周长为：____。

近些年来，消费对经济增长的拉动作用不断增强。商务部部长钟山在2017年全国“两会”期间表示，消费已经成为拉动中国经济发展的第一大拉动力。扩大国内消费，事关国家经济社会发展全局。下列措施能够扩大消费需求的事（  ）

①提高银行存款准备金率

②继续缩小城乡收入差距

③最根本的是提高人们的收入水平

④通过供给侧改革提高商品的质量

某烃类化合物A的质谱图表明其相对分子质量为84，红外光谱表明分子中含有碳碳双键，核磁共振谱表明分子内所有氢原子都处于相同的化学环境，由此推测

（1）A的结构简式为　____；

（2）A中的碳原子是否都处于同一平面？____ （填“是”或者“不是”）。

        These days, many students like playing 3D games. Do you know what 3D games are like? In most 3D games, game players need to control (控制) a character. The character can be a robot or a soldier (士兵). Game players usually use the mouse to make the character move around in his own world. Game players can find things such as food and weapons (武器) to help them go on with the game. The character can go straight, sit down, turn left, turn right or pick up things in the game.
        Some 3D games have many levels (等级). The character needs to finish different goals for each level. Game players can play against their computers, and sometimes they can play with other players online. It’s great fun to play 3D games. But playing 3D games for long is not good for our study.

资本主义经济学的鼻祖亚当．斯密无论如何也不曾想到，在经过了几百年风霜雪雨的洗礼之后，他理想中的经济自由化竟然在现实中会遭到如此的困境，并出现如此的“异化”……这种异化在十九世纪晚期表现为（    ）