简述光纤传输的主要优点。
参考答案：传输容量大、抗干扰能力强、传输距离远。
It seems that the more lovely an animal is , the more it _____our health. As the saying goes, “if you want to be loved, get a dog.”
A．harms
B．troubles
C．benefits
D．treats
下述不属于内分泌腺的是（）
A、垂体
B、甲状腺
C、唾液腺
D、肾上腺
