茶叶中含有（）多种化学成分。
A、100
B、200
C、500
D、1000
参考答案：C
We are thinking about ________ can be admitted into our club. The number of members is limited.
A．who
B．what
C．which
D．whether
ETFs are similar to closed end funds in which of the following features Do not sell or redeem Often trade away shares after IPO from NAV（）①A. Yes Yes ②B. Yes No ③C. No Yes
A. ①
B. ②
C. ③
