Помогите пожалуйста!!!!1. The keys ______ already a) were found b) found

Помогите пожалуйста!!!!
1. The keys ______ already
a) were found b) found c) have been found d) was being found
2. The book ______ twenty years ago
a) is written b) was written c) have been written d) had been written
3. The first stamp _____ in England in 1837
a) invented b) is being invented c) was invented d) will be invented.
4. Red Square ______ by millions of tourists next year.
a) is visited b) visit c) has been visited d) will be visited
5. Every year thousands of presents ________ before New Year.
a) will be sold b) are sold c) have been sold d) are being sold