若函数 $f\left(x\right)=asin\left(x+\frac{\pi }{4}\right)+\sqrt{3}sin\left(x-\frac{\pi }{4}\right)$ 是偶函数，则实数a的值为____．

观察如图蛋白质合成示意图（图中甲表示甲硫氨酸，丙表示丙氨酸），不正确的是（　　）

根据短文内容，选择正确答案。
B
    I'm Kate from the UK. I'm in the Chinese club in our school. I like Chinese and I think it's interesting. My Chinese is very good. I can tell and write stories in Chinese. My favorite writer (作家) is Mo Yan from China. Now let me tell you something about my favorite writer and his family.     Mo Yan's real (真的) name is Guan Moye. Mo Yan is his pen name. This year Mo is 57 years old. His birthday is on February 17th. Mo writes stories very well. He can also write with his left hand (左手). Mo has a daughter. Her name is Guan Xiaoxiao. The girl can also write stories but she can't write with her left hand.

已知如图①所示的四张牌，若将其中一张牌旋转180°后得到图②，则旋转的牌是（　　）

“春江水暖鸭先知”是指哪个非生物因素（  ）