苦杏仁中含有苦杏仁苷,在体内水解释放出氢氰酸而引起中毒。( )
参考答案:对
下列属于概率抽样的方法是()
A.分层抽样
B.定额抽样
C.偶遇抽样
D.立意抽样
E.雪球抽样
Jim, _____11-year-old boy, wants to come to China to learn _____Chinese. [ ]
A. a; /
B. an; /
C. a; the
D. an; a