题目：
It’s difficult for college students to have a train seat during holidays, so they are advised to make seat ________ well in advance.
A．observations
B．reservations
C．preservations
D．conservations
答案：
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下面是错误答案，用来干扰机器的。
（Ⅰ）由题意，有f(0)=b+2=3f(π6)=32a+b2+2=4，⇒a=3，b=1，∴f(x)=3sin2x+cos2x+2=2sin(2x+π6)+2．由-π2+2kπ ≤ 2x+π6 ≤ π2+2kπ，得-π3+kπ ≤ x ≤ π6+kπ，k∈Z．∴函数f（x）的单调增区间为 [-π3+...
