单项选择 —________ do you take violin lessons? —On weekends. A．When B．How C．What D．Where
By the time Mary gets home, her aunt ____ for London to attend a meeting. A. will leave B. will have left C .leaves D. left
（05年江苏理综）光线以某一入射角从空气射人折射率为的玻璃中，已知折射角为30°，则入射角等于 A.30° B.45° C.60°
If he failed, it ___________ a bitter disappointment for his parents. A. were B. will be C. would be D. be
______, the healthier you will be． A．The more money you get B．The taller you are C．The more you eat D．The better h
下列物质中，目前计入“空气污染指数”项目的是( ) A．氮气 B．氧气 C．稀有气体 D．可吸入颗粒物
下列仪器不能用作化学反应容器的是（） A. 烧杯 B. 试管 C. 量筒 D. 集气瓶
