答案：A
小明将奶奶的老花镜正对着太阳光，在透镜的另一侧移动光屏，当距透镜5cm时，屏上出现最小最亮的一点，则老花镜的焦距约是______cm．
My aunt is a writer. She ______ more than ten books since 1980. [ ]
A. writes
B. wrote
C. has written
D. will write
