如图所示，在光滑水平面上有甲、乙两木块，质量分别为m₁和m₂，中间用一原长为L，劲度系数为k的轻质弹簧连接起来，现用一水平力F向左拉木块甲，当两木块一起匀加速运动时，两木块之间的距离是（   ）

期中测验，小芸的成绩较过去比有了很大的退步。她及时查找了自己的问题，积极向同学寻求更理想的学习方法。对小芸的行为，我们认识正确的是（  ）

Joe Brown had a shop. He sold(卖) meat in his shop . One Thursday a woman came into his shop at five to one . “I’m sorry I’m late,” she said. “I need some more meat for my dinner tonight.” Joe had only one piece of meat in his shop. He took it out of the fridge and said, “This is＄6.50.”  “That piece is too small.” the woman said, “haven’t you for anything bigger?” Joe went into the room behind his shop, put the piece of meat into the fridge, took it out again and closed the door with lots of noise. Then he brought the piece of meat to the woman and said, “This piece of meat is bigger and more expensive. It’s ＄8.75.” “Good,” the woman said with a smile,“give me both of them.”

读图，回答问题。