go, give, fly, fasten, ride, obey, sail, drive, cross, wear
1. ......... a bike
2. ......... a car 
3. ......... a plane
4. ......... a boat 
5. ......... a signal
6. ......... a helmet
7. ......... the seatbelt
8. ......... by air
9. ......... a bike
10. .......... traffic rules
Giup mình.

\(2^{x+3}+2^{x+5}=160\)
\(2^x.2^3+2^x.2^5=160\)
\(2^x.\left(2^3+2^5\right)=160\)
\(2^x.\left(8+32\right)=160\)
\(2^x.40=160\)
\(2^x=160:40\)
\(2^x=4\)
\(2^x=2^2\)
\(x=2\)
Vậy.....

...... ( In/ On) holidays the shop opens for business as usual
When I saw Hoa, she was holding a pocket English dictionary ( at/in/on) ........ her hands
What do you usually do ( at/in/on) Tet?
giup minh voi a, camon nhieu.

his class begins ...... ( in/on) two minutes
the library is open...... ( in/on) weekdays only
these things happened ....... ( at/in) the past years
did you hear the cock crow.......(in/at) dawn