- I can hardly believe my eyes. Is that you, Joy?

- Yes. It has been almost ten years           we were together.

阅读材料，回答问题。

材料一：

材料二：近年来，我国科技创新领域亮点频出：“神舟”飞天、“嫦娥”探月、“蛟龙”潜海、C919大型客机总装下线……这极大振奋了民族精神，提升了我国国际地位。但也要看到，我国科技发展水平总体不高，科技对经济增长的贡献率远低于发达国家水平。不少产业的核心技术仍受制于人，出现很多“卡脖子”问题。放眼全球，新一轮科技革命和产业变革蓄势待发，创新已经成为大国竞争的新赛场，谁下好创新这步先手棋，谁就能占领先机、赢得主动。

分别标有“6V，2W”和“12V，8W”的两个灯泡，串联后接在电路中，为使其中一个恰能正常发光，加在电路两端的电压应是（　　）

Fill in the blanks with the proper forms of given words.

I helped my mother to buy some beef and three____ (potato) for supper today.

"Belt and Road"（一带一路) are the two wings of developing Asia in the____ (twenty-one) century.

Please keep____ (silence) in the concert hall because people are enjoying Lang Lang's piano performance.

Candy ____ (lay) out the tea, fruit and snacks on the table and waited for the visitors.

.With the development of technology, mobile phones are ____ (wide) used these days.

如图所示装置中，cd杆原来静止．当ab杆做如下哪些运动时，cd杆将向右移动(说明：导体棒切割速度越大，感应电流越大，导体棒匀速切割磁感线时，感应电流恒定)(   )