—Shall I help you carry your travel case to the train ,Granny? —Oh,no,my boy.It is heavy.Thank you anyway.
Pandas are native ______ China.
No product is allowed to go into the market if it fails to _____ the quality standard.
When was it _____ your parents took you to Hangzhou?
It is everyone’s duty to ______ our school a pleasant place to learn in.
Ever since my brother graduated from the university, he _______ in the present company for 15 years and he is now chief engineer of the company .