A-A+
______ have been made for nearly three decades
问题详情
______ have been made for nearly three decades to increase the amount of precipitation from clouds by seeding them with salt or silver iodide.
A．Devices
B．Hypotheses
C．Attempts
D．Commissions请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：C
解析：名词辨析A Devices装置，设计，策略，设备；B．Hypotheses臆测，假定；C．Attempts努力，尝试，企图；D．Commissions委任，代办(权)，佣金；本题讲的是：已做了近三十年的尝试，试图在云层中加入盐或碘化银来增加降雨量；因此C为答案。
