在关系代数中，五个基本操作的运算符的中文名称是_____、_____、_____、_____和_____。

Fill in the blanks with appropriate coordinator or subordinator:______________ a well-balanced diet ___________ adequate sleep is needed for good health

Which do you think is ________, health or wealth？

_______________will not continue if an ongoing operation is changed or deletedA、

抗体的生物学活性是______、______、______、______、______。

五脏的生理功能主要是________和________；六腑的生理功能主要是．________和________。

29．__________ when you are on the bus or bike．

Which do you think is _________________important, health or wealth?

And they can ______their passports______，making leaving or “escaping” virtually impossible.

除病毒为_______微生物外，真菌属______型微生物，大部分微生物细胞为_______型微生物。

HUB是一种网络设备，它的中文名称叫 ______。

HUB是一种网络设备，它的中文名称叫______。