【单选题】Tom wants to study at _______ university in Europe, but hasn't decided which one to go to yet.
【单选题】The early pioneers had to many hardships to settle on the new land.
【单选题】The trade union intended to call on the workers to go on strike ______ the government’s limitation on exports.
【单选题】一般来说,植物性食物因含有( ),比动物性食物蛋白质消化率低。
【单选题】下面换热器的调节介质为热媒油,若物料出口温度过低会导致物料结晶,则执行器可选为()
【单选题】Tom wants to study at ______university in Europe, but hasn’t decided which one
【单选题】( 32 ) 设有学生信息关系 STUDENT ( sno , sname , sex , age , dept ) 。 “ 查找信息系 ( IS 系 ) 中年龄小 于20 岁的学生的姓名 ” ,该操作正确的关系代数表达式是 Ⅰ . π sname ( σ dept= ’ IS ’ ∧ age<20( STUDENT )) Ⅱ . σ dept=’ IS ’ ∧ age<20 ( π sname...