together和时间状语放在句末的前后位置

时间状语有短语也有从句
1. It rained for three days together.
一连下了三天雨.
2. She can sit reading for hours together.
她能连续几个小时坐在那儿看书.
3. Get all the ingredients together before you start cooking.
把所有材料都放在一起再动手烹饪.

is,together with /with 等词都是用于对主语的补充，作题时可以不看，因而原句可写成english ____not easy to master，显然选IS