Spring tides are tides that__________A. have lows lower than normal and highs higher than normalB. have lows higher than normal and highs lower than normalC. are up predictableD. occur in the spring of the year

本题考查春潮（spring tides）的形成原理及特征。解题核心在于理解太阳和月亮的引潮力叠加导致的极端潮位现象。关键点包括：

1. 春潮发生的时间（新月和满月期间）
2. 引潮力叠加使高潮更高、低潮更低
3. 排除干扰选项（如“春季”“不可预测”等常见误解）

选项分析

A. have lows lower than normal and highs higher than normal

正确。春潮因太阳和月亮的引潮力方向一致，叠加作用使高潮高于正常水平，低潮低于正常水平。

B. have lows higher than normal and highs lower than normal

错误。此描述对应小潮（neap tides）特征，发生在太阳和月亮引潮力方向成90°时，与春潮相反。

C. are unpredictable

错误。春潮由天体运行规律引起，可通过天文历计算，属于可预测现象。

D. occur in the spring of the year

错误。“Spring tides”中的“spring”意为“大潮”，与季节“spring”同词异义，春潮全年均可发生。