造成流脑大流行的主要因素是
A．人群免疫力下降，新的易感者增加
B．菌群毒力增加
C．菌群变异
D．带菌者增多
E．细菌产生耐药
参考答案：A
On Oct. 29, the famous Chinese pianist Lang Lang was named as United Nations Messenger of Peace, ________ means he will help promote(促进) global education.
A．which
B．what
C．that
D．It
下列字形和加点字注音全部正确的一项是( )(2分)
A．堕落(duò)澄清(dēnɡ)酝酿(niànɡ)苦心孤诣
B．腆着(tiǎn)恣睢(zì)蓬蒿(ɡāo)荒草萋萋
C．羼水(chàn)荇藻(xìnɡ)粗拙(zhuō)心旷神怡
D．诓骗(kuānɡ)绽出(zhàn)匀称(chèn)猝不急防
