—Where's my soccer ball?
—_____ under the bed. [ ]
A. It
B. Is
C. It's
D. Its
答案:C
一个角与它的余角相等,则这个角为[ ]
A.45°
B.90°
C.45°或90°
D.50°
引导学生设立目标,目的是引导学生在学习上多投入精力。