下列能对食品质地产生影响的酶有（）
A.果胶酶
B.纤维素酶
C.淀粉酶
D.脂肪氧合酶
参考答案：A, B, C
With his attention _________ on his book, he didn’t notice someone entering his room.
A．concentrating
B．concentrated
C．to concentrate
D．concentrates
根据记账凭证逐笔登记总分类账是____会计核算程序的主要特点。
A．汇总记账凭证
B．科目汇总表
C．多栏式日记账
D．记账凭证
