地球公转到远日点附近时,正值北京的[ ]
A. 夏季
B. 秋季
C. 冬季
D. 春季
答案:A
She has studied in this school _______ she was seven years old. [ ]
A. since
B. if
C. until
D. after
弹簧测力计是测 的仪器,在下图中,弹簧测力计的读数是________N。