题干
— What do you usually do in the morning?
—I often practice_______English.
A：speak
B：to speak
C：speaking
答案(点此获取答案解析）
C
— What do you usually do in the morning?
—I often practice_______English.
A：speak
B：to speak
C：speaking
、M的两物体，系在一根过定滑轮的轻绳两端，M放在水平地板上，
