In this country, the weather is usually awful.
A:very nice
B:very fun
C:very bad
3+7=____
2+1=____
3-1=____
4+2=____
读“塔里木盆地图”,回答下列问题。
①调节平衡螺母,使指针静止时指在标尺中间.
②将砝码放回砝码盒,将游码拨放到刻度尺零处.
③左右两个盘上各放一张质量相等的纸.
④右盘放入5g砝码,将游码拨到1g处.
⑤向左盘上加食盐直到天平平衡.