与在湖里游泳相比，我更喜欢乘船游览仙岛湖。我认为在湖里游泳不安全。
I ________ taking a boat trip on the Xiandao Lake ________ swimming in it. I don’t think ________ ________ safe to swim in a lake.
你房间的灯还亮着。你离开之前不要忘记把它们关掉。
The lights in your room are still on. Don’t forget _________ _________ __________ _________ before you leave.
这对双胞胎兄弟有一个共同点：面临困难时他们从不轻易放弃。
The twin brothers have one thing _________ _________: they never _________ __________ easily when they face difficulties.
The more careful you are, the fewer________（错误）you'll make.
It is very noisy outside and we________（想知道）what has happened.
What were you doing when the heavy rain________（突然地）came?
