پرسش‌ها با تگ (گرامر)

تفاوت حال کامل و حال کامل استمراری و همچنین گذشته کامل و گذشته کامل چیست ممنون میشم با مثال توضیح بدین 

Over 1900 years ago, ………, who worked in Alexandria, Egypt, classified the stars  by their brightness.

 Although Margaret Mead had several assistants during her long investigations of  Samoa, the bulk of the research was done by ……… alone.  

 You'd rather I kept quiet about it ....... (a) did you? (b) had you? (c) wouldn't you? (d) do you?  He used to work in the city ....... (a) had he? (b) does he? (c) has he? (d) didn't he? ...

تفاوت The currency in China is different from that in Australia  و  The currency in China is different from  one in Australia. لطفا از هوش مصنوعی کپی نکنید ممنون میشم

The foreign student advisor recommended that she ……… more English before  enrolling at the university. 

 The more advanced the specialization in production and the more complex the  economy, ……… to make any given good reach its ultimate user by using barter. 

………, Luxor did not reach preeminence until about 2,000 B.C.

سلام دوستان وقتتون بخیر لطفا در مورد علت استفاده دو تا زمان simple past در جمله پایین توضیح بدین. منظورم knew و was هست. همچنین، میخواستم بدونم چرا فعل remains رو بصورت has remained نیاورده؟ آیا است ...