1. see
-> If 1 : If + S1 + Vs/es, S2 + will + Vinf
2. had done
-> After + quá khứ hoàn thành, quá khứ đơn
3. to ride
-> how + to V
4. scientists ( n : các nhà khoa học, S + be + one of + N số nhiều )
5. will be watching ( at 9pm tomorrow: tương lai tiếp diễn )
6. using ( avoid + Ving )
7. had ( If 2: If + S1 + V2/ed, S2 + would + Vinf )
8. invention ( sự phát minh )
II
1. will be sitting
2. to have
3. announced
4. comfortable
