问题补充:
Our teacher suggests English every day to improve our spoken English.
A. practising to speak
B. to practise to speak
C. to practise speaking
D. practising speaking
答案:
A. practising to speak
B. to practise to speak
C. to practise speaking
(答案→)D. practising speaking
解析:practise/suggest+doing,不能跟不定式;故选D。