我国《证券法》规定,证券持有人所持有的证券上市交易前,应当全部托管在()。
A.证券公司
B.证券交易所
C.资信评估机构
D.证券登记结算机构
参考答案:D
Everyone can play an important part in society. As members, we should try our best to do __ .
A. how we should do B. what should we do
C what we should do D. how should we do
什么是菌种,菌种可分为哪些类型?