委内瑞拉、哥伦比亚、厄瓜多尔、秘鲁和玻利维亚等国的驻华大使，每年6月5日都要到北京的朝阳公园向“拉丁美洲解放者”的铜像进献花篮。该铜像人
挑选适宜播种的种子时，需要测定种子的发芽率，具体做法是（ ） A．随机抓取20粒种子，发芽率超过90%
已知函数f(x)＝g(x)＝f(x)＋x＋a.若g(x)存在2个零点，则a的取值范围是( ) A．[－1,0) B．[0，＋∞) C．[－1，＋∞) D． [1，＋∞)
As human beings we like to think of ourselves superior(高级) to other creatures, but sometimes we can learn something from them.. One day at lunchtime I _36_my office, took out a sandwich, and _3
_____ it have been the failure to pick up directions from the ground control that caused the air crash? A. Must B. Could C. Would D. Should
He’s got himself into a dangerous situation _____ he is likely to lose control over the plane. A. where B. which C. while D. why
根据相关化学概念和原理，下列判断正确的是（ ） A．若某反应的生成物总能量低于反应物总能量，则该反应为吸热反应 B．若将反应Fe + 2Fe2+ = 3Fe3+设
用
表示
. 
.