Давайте разберёмся с вашими предложениями и выберем правильные слова. Вот правильные варианты завершения предложений:
a. Log in to the website and go to 'my account.'
Вариант: A - at
b. Which button should I click?
a. I don't get as much emails as you do.
Вариант: C - much
b. There aren't any Wi-Fi hotspots near here.
Вариант: D - any
a. I'm usually very busy, so I spend a little time playing computer games.
Вариант: C - a little
b. There's little information on this website; it isn't very useful.
Вариант: D - little
a. He didn't answer his phone. He might not have heard it.
Вариант: B - might
b. Let's call later, they must be having dinner now.
Вариант: D - must
a. My phone battery can't have run out yet. I've only just charged it!
Вариант: A - can't
b. Matt's games console must be working. He's reading a book!
Вариант: D - must
a. Old technical gadgets can be harmful to the environment.
Вариант: D - to
b. My MP3 player is similar to my sister's. The only difference is the colour.
Вариант: D - to
a. My friend is annoyed with me about the comment I posted on her wall.
Вариант: C - with
b. How many people do you know who are obsessed with online games?
Вариант: C - with
Надеюсь, это поможет вам в подготовке! Если у вас есть ещё вопросы, не стесняйтесь спрашивать!