4. Go there by bus instead of by bike in case of it rains.

　　5．Child although he is，he can tell black from white.

　　【答案】　1.if→unless　2.if→whether　3.Provide→Provided/Providing　4.去掉第二个of　5.although→as/though

　　写邀请函及其回复

　　邀请信属于应用文，主要用来邀请某人参加宴会、庆祝活动或会议等。邀请信可分为正式的邀请信(请柬)和非正式的邀请信两种。

　　1．英语邀请函一般应该包括以下内容：(1)诚挚邀请对方参加某一活动；(2)概况介绍活动的内容和安排；(3)再次表示诚意。

　　2．收到邀请函写回函表示接受邀请应包括以下内容：(1)感谢；(2)表示确定会赴邀。

　　3．拒绝邀请应包括以下内容：(1)收到邀请；(2)表示感谢；(3)阐述不能赴邀的原因；(4)表示遗憾和良好的祝愿。

　　[亮点句式]

　　1．邀请函常用句式

　　①I'm writing to invite you to...

　　②I wonder if you can come...

　　③It is my pleasure for me to invite you to...

　　④My family and I would feel much honored if you could come.

　　⑤We are looking forward to your coming with great pleasure.

　　⑥I hope you're not too busy to come.

　　⑦Please confirm your participation at your earliest convenience.

　　⑧I am longing to see you soon.

　　2．接受邀请常用句式

①Thank you for your invitation to...