5. Have you decided on a place for the picnic?
你选好野餐的地点了吗？
还能这样说：
Have you made your mind where we go for the picnic?
Have you already selected a place for the picnic?
6. Can you come this Saturday?
星期六怎么样？
还能这样说：
Do you have time this Saturday?
Are you available this Saturday?
应用解析：
Saturday-to-Monday 周末；
Hospital Saturday 为医院募捐的星期六
7. Do not forget to bring matches, or you'll be unable to build a campfire.
别忘了带火柴，否则就点不着火了。
还能这样说：
You must take matches with you, or you will not make a fire.
You have to make a campfire with matches.
谚语：
The fire which lights us at a distance will burn us when near.
远火照明，近火灼人。
8. You need to put on sunglasses for protection against the strong light.
你需要戴上墨镜以防强光的照射。
还能这样说：
Sunglasses are a must, or you may be hurt by the strong light.
Wearing sunglasses is very necessary which can help you avoid the strong light.
应用解析：
be going strong 健康良好，保持旺盛精力，仍然硬朗；
be strong against 坚决反对；
be strong in 擅长；
be strong under 在……坚定不移