1 . When shopping online, here are a few simple steps you can take to ________.

A．keep being cheated	B．keep from being cheated
C．be kept from being cheated	D．be kept being cheated

2 . ________ another opportunity, I will never waste precious time ________ online games.

A．Given, playing	B．Giving, to play
C．If to be given, playing	D．If giving, to play

3 . Impossible ________ it is for us to live in an environment free of pandemic, we had better try our best to avoid ________.

A．however; affected	B．though; to be affected
C．although; being affected	D．as; being affected

4 . The key to ________ a great artist is to know how ________ the rules with breakthrough.

A．becoming; to balance	B．become; to balance
C．becoming; balancing	D．become; balance

5 . The knife needs           ; it’s not sharp.

A．edging

B．edged

C．to edge

D．being edged

6 . American school buildings are old and many face major challenges when it comes to ______ their indoor air quality.

A．upgrade

B．upgrading

C．being upgraded

D．upgraded

7 . Phone sales have been in gentle decline since 2016, as slower technological improvement has led to people ________less often.

A．to upgrade

B．upgraded

C．upgrading

D．having upgraded

8 . The accident was really unexpected. I did try to avoid __________ the car in front of mine, but I failed.

A．to hit

B．to have hit

C．having hit

D．hitting

9 . The current medical system needs ______.

A．reforming

B．to reform

C．to be reformed

D．both A and C

10 . Please excuse me for _______ you just now.

A．offend

B．having offended

C．having been offended

D．offending