中国大学MOOC: Relational algebra consists of six basic operations: select, __________, union, set difference, cartesian product, and rename.

The rain did ______ to the game. A: take a difference  B: put a difference C: have a difference  D: make a difference

Within a resource-plan definition， what differentiates a top-level plan from a subplan？（） A: A subplan has the PLAN_SUB parameter value set to SUB B: A top-level plan has the GROUP_OR_PLAN parameter set to the name of the subplan in the resource-plan definition C: There is no difference in the resource-plan definition D: A subplan always has the CPU_MTH parameter value set to RATIO E: The string TOP_LEVEL is appended to the name of top-level resource pla

A cultural difference could be a difference in______

What’s the main obstacle in global communication? A: Climate difference B: Racial or national difference C: Geographical difference D: Cultural difference

set_a = {1, 5, 10}, set_b = {1, 10, 12} , 则set_a.difference(set_b)的结果是 A: {5} B: {1} C: {10} D: {12}

Cross-cultural factors in international business negotiation includes: A: Difference in contract B: Difference in negotiating styles C: Difference in criterion and member of negotiators D: Difference in negotiating objectives

Climate change may be a big problem, but there are many little things we can do ______. A: making a difference B: to make a difference C: made a difference D: make a difference

When you are learning driving a car, it _____ whether you have a good teacher or not. A: makes a difference B: has a difference C: makes no difference D: has no difference

What is the difference between Madam Chiang’s Nutritious Beauty Porridge and ordinary porridge? A: It is an elixir. B: Its recipe was set by Madam Chiang. C: It uses sweet soy milk to boil the porridge. D: It is cooked longer.