将一枚硬币投掷两次，至少出现一次正面的概率为()。
A. 0.25
B. 0.5
C. 0.75
D. 1
查看答案
A．M1B-1B．MIB-2C．MIB-3D．MIB-4
A. M1B-1
B. MIB-2
C. MIB-3
D. MIB-4
Cats sleep much more than horses do partly because cats ________.
A. need more time for restoration
B. are unlikely to be attackers
C. are more active than horses when they are awake
D. spend less time eating to get enough energy
In the following essay, each blank has four choices. Choose the most suitable one from the
A. unique
B. separate
C. same
D. dependent
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