He don't know if (wether) we will arrive on time tomorrow morning 他不知道我们明天早上是否能准时到达
146 if :如果,假如(全部接一般时态)+条件语态从句
eg: I'll go to LuZhou if it does't rain 假如明天不下雨,我就去泸州 If they change the plan they will let me know 假如他们要改变计划,他们会让我知道的
I'll go to England ,if I have enough money next year 如果我明年由足够的钱,我就要去英国
147 in one's opinion = sb think 某人认为
148 in some ways 在某些方面
149 in the end = finally(adv) 最后
150 in the north of… 什么在什么的北方 (north 北 sowth 南 west 西 east 东 )
151 in the sun 在太阳下
152 increase 增加
eg : They've increased the prece of petrol by 3% 他们把石油价增加了3%

