They fulfilled the plan earlier than they ________.

A. have expected

B.were expecting

C.expected

D.had expected

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We could not have fulfilled the task in time if it ______for their help.A．was notB．is notC
We could not have fulfilled the task in time if it ______ for their help.
A．was not
B．is not
C．had not been
D．has not been

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They overcame all the difficulties and fulfilled the plan two months ahead of time, ______. (这是我们没有预料到的)


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以下对promiseA+规范描述正确的是？（）

Much of a parent's job is to provide the gifts of caring, love, and emotional support to children. But one gift is often beyond their reach: the resources to meet the financial demands of college tuition.
For more than 54 years, the United Negro College Fund has fulfilled the dreams of deserving students by closing the gap between the cost of college and what their parents can afford. More than 300,000 students have graduated from United Negro College Fund member colleges since 1944, and 54,000 more axe currently enrolled (入学).
The oldest and most successful minority higher education support organization, the United Negro College Fund is a combination of 39 private, historically black member colleges and universities. Since its founding, it has raised more than $1.3 billion to keep the dream alive for needy families across the country.
What is it that makes the United Negro College Fund so important to America's families？ As well as raising funds and giving technical support to member colleges and universities, it creates hope and opportunity by providing financial assistance to deserving students. Consider the contributions of just a few of the distinguished graduates who have realized the benefits: civil rights activist Dr. Martin Luther King, Jr.; opera diva Leontyne Price; Olympic track star Edwin Moses; and filmmaker Spike Lee.
Most parents feel embarrassed when their children graduate from high school because they can't ______.
A．afford their children's college tuition
B．offer their children emotional support
C．look after their children
D．give them gifts on their birthdays

厚朴、朴树（）

对于任意两个事件A与B,有P（A+B)=（).

相对压强 p 与绝对压强 ′、大气压强 pa关系式（)。

命题公式P→（P∨￢P)的真值是______．
命题公式P→(P∨￢P)的真值是______．

下列哪些是通用的水泥代号（）。