题目

老师给小明一个凸透镜、一把刻度尺、一张白纸，让他测出这个凸透镜的焦距。请你帮助他完成。可画图辅助说明。 答案：解：如图所示： We’re in a stage _____ it’s still too early to say who will win the most votes and become the new President. A．thatB．whereC．whichD．what