如图所示，质量为m=0.2kg的小球从平台上水平抛出后，落在一倾角θ=53°的光滑斜面顶端，并恰好无碰撞的沿光滑斜面滑下，顶端与平台的高度差h=0.8m，斜面的高度H=7.2m．g取10m/s² （sin53°=0.8，cos53°=0.6），求：

小明同学在“用天平测物体质量”的实验中：

（1）首先取来托盘天平放在水平桌面上，游码移到标尺的零刻度处，若天平的指针静止在图甲所示位置，则可将平衡螺母向____ （选填“左”或“右”）调节，使天平横梁在水平位置平衡；
（2）天平调节水平平衡后，小明按图乙所示的方法来称量物体的质量，小华立即对小明说：“你操作时至少犯了两个错误．”小华所说的两个错误是
①____  ；
②____ 。
（3）小明虚心地听取了小华的建议，重新进行操作．在称量过程中，又出现了如图甲所示的情况，他应该____；
（4）天平再次调到水平平衡后，所用砝码和游码位置如图丙所示，那么小明所称量物体的质量是____ g。

家庭轿车的大量使用可能引发的环境问题是（   ）

A Party

Donny: Kim and I want to throw a goodbye party for Chuck.

It's this Saturday night at Kim's house.

Tina: That's a good idea. What do we need to do?

Kim: We need to buy some food and drinks. Tina, please meet me at 10 o'clock on Saturday morning. We'll go shopping.

Tina: OK!

Donny: Pam, you have a lot of great CDs. Please bring your CDs.

Pam: Sure! I will take care of the music.

Tina: Did you invite Chuck's other friends?

Donny: Yes. We already invited them and gave them Kim's address. It will be fun.

Tina: Wow! I can't wait for the party.

Chuck: Hey! What party?