商业银行办理票据承兑、汇兑、委托付款等结算业务,应当按照规定的期限兑现,不得压单、压票或者违反规定退票。
参考答案:对
Some students have trouble ____ grammar while others have difficulty ____ new words. [ ]
A. in; remember
B. for; to remember
C. on; remembering
D. with; remembering
为使人血浆pH保持在正常的范围,[]/H2CO3]应保持在()
A.10:1
B.1:15
C.20:1
D.25:1
E.1:20