太阳黑子循环周期的英文

• sunspot cycle

• 循环:    circulate; circle; round; re ...
• 周期:    period; cycle; circle; revol ...
• 太阳黑子循环:    sunspot cycle
• 太阳黑子周期:    su ot cycle; su otcycle; sunspot cycle; sunspot periodicity; sunspotcycle
• 太阳黑子活动周期:    period of sunspot activity; sunspot activity period