某学生将2.5%的尿素滴加在载玻片上的蚕豆表皮上，观察到植物细胞的质壁分离。2小时后企图再次观察时却发现理想的视野找不到了，原因是[ ]

A．错拿了对照样品

B．时间过长，细胞壁也收缩了

C．溶质颗粒被缓慢吸收，使水分再度进入细胞

D．2小时前观察到的现象是假象

There ______many restaurants in town, but they _________ eat the food there at first.

A．used to have, didn’t use to

B．used to have, didn’t used to

C．used to be, didn’t use to

D．used to be, didn’t used to