水溶性维生素的共同特点为( )。
A.一般有前体物
B.不易吸收
C.会积蓄中毒
D.宜每日供给
参考答案:D
The lake looks like a big mirror in which the________of the trees is very clear.[ ]
A. shade
B. shadow
C. reflection
D. reaction
For Candlin, the meaning ______ involved in making choices and decisions lies at the heart of the language learning process.