The shopkeeper did not want to sell for      he thought was not enough.

细胞的生活依赖细胞各结构的分工合作，发生着非常复杂的物质、能量和信息的变化，这些活动的控制中心是（　　）

The extraordinary success of Conan Dole, mainly with his Sherlock Homes, has_________ the market with detective stories.

一个有理数与它的相反数的积（    ）