I wonder ______ they will arrive on time.[ ]
A. to be
B. whether
C. that
D. who
答案:B
青少年牙周炎患者的龈下菌斑中,主要为()。
A.产黑素类杆菌和血链球菌
B.放线共生放线杆菌和嗜二氧碳杆菌
C.产黑素类杆菌和嗜二氧碳杆菌
D.产黑素类杆菌和放线共生放线杆菌
E.血链球菌和放线共生放线杆菌
—Have you written anything on Chinese traditional food so far?
—______, but I have a plan for it. [ ]
A. Ever since
B. Later on
C. Not yet
D. From now on